tracking well
and tracking well in following seas often go hand-in-hand. As an example, I find that the P&H Sirius is excellent in that department, but it is also much harder to turn than the Capella. I’m 6’0" 175 lbs., 10.5 foot size, 32" inseam. I have one of the original square hatched Capellas that has been worn to pretty much the graveyard at this stage (quite old and a lot of use), replaced by a carbon/kevlar version. I consider it my playboat. They’re incredibly maneuverable and a heck of a lot of fun. If my paddle is likely to involve steep following waves that I want to travel with vs just playing in, a step up in that department for me would be a Quest LV or Nigel Foster Legend or something in that department. They both track better and are easier to control in following seas (my experience is free of skeg here - drop the skeg on your Capella and you have a whole new boat, as with the Quest LV or Legend or whatever). They turn not as easily as the Capella, but still quite well, and they allow you an increase in speed should you ever desire to use it. I know these aren’t boats that you’re considering. This is just meant to address the following sea issue. All boats can get squirrelly. Something like the Sirius is probably not what you’re looking for (behaves like nobody’s business in A to B paddles in whatever conditions, but not particularly playful), but it’s an example of how excelling in one department can compromise another. If I’m just going to play in surf and ride some waves,I love the Capella. It isn’t necessarily the same as being well-mannered in a following sea when you’re trying to go somewhere. I’d make the decision on what’s important to me and a good understanding of what type of boat best matches. I know the models you have listed are considered excellent all-around boats, and from what little you’ve said, they very well could be the best fit. I don’t have a Romany, so I would probably filter carefully for an objective opinion on these boats’ behaviors in a following sea vs one another.
RM Romany coaming
Though the deck and hull maybe roto-molded in the same factory as Valley boats, the RM Romany has a composite coaming which is epoxied and riveted in place.
Aside from the foot pegs, problems with the attachment of the coaming is what I’ve heard the most.
Avocet good in those conditions, but…
> … steep faced short period waves is that the extra
length might be a liability? This is probably the heart of my problem,
The Avocet is pretty good in conditions like that, but not as good as, say, an Explorer, Nordkapp LV, Aquanaut, etc – and probably the Cetus/Scorpio, though I have not personally paddled the latter in those conditions. It’s really more a matter of hull shape than raw length. I find the Avocet a little corky in steep chop by comparison with those others.
picking the right balance of tracking
and maneuverability without paddling the boat.
Please do try to paddle the boat before you decide. It’s almost indispensable in picking a boat.
–David.
similar experience
I was quite dissatisfied with Avocet RM in the following seas. However, I tried friends copy and was extremely surprised to notice huge difference in handling. Difference? - different year boat, and seat placement. His was ~1 forward from my. Currently I am fiddling with seat placement in my Avocet.
Avocet and Romany
First off, I’ll jump on the “try before you buy” bandwagon. Unless it’s absolutely prohibitive to do so. Yes, you may spend a fair bit of money in the process, but I’d imagine it would be less onerous (both financially and otherwise) than ending up with a boat you don’t like and having to sell it and find another.
As for the three boats you mentioned, I’ve paddled the Romany (both regular and S) and Avocet in composite. The first thing that occurs to me is that a Romany S might be too large for you, unless you have proportionally long legs. I’m just a hair over 6’ and weigh 180, and the Romany S did not come anywhere near to fitting me. In particular, I couldn’t get good contact with the thigh braces due to the height of the deck.
Between the regular Romany and Avocet, I preferred the Romany, mostly for fit issues. Performance-wise, they seem pretty close, although I didn’t paddle the Avocet for very long. I did, however, paddle a Romany in some pretty dynamic water conditions and it performed very well. Quite manueverable and lively, but no slouch in straight-ahead paddling either.
Consider the Riot Brittany
I paddle a lot of boats (including pretty extensively the Avocet)-- and I keep coming back to the Brittany as a great all-around hull. It doesn’t have the name recognition of the others, but probably should. The polyethylene is good quality and the outfitting is excellent. I especially like the thigh hooks and backband. The Brittany handles rough conditions well, is faster and tracks straighter than the Avocet, yet it still turns readily – and is made right there in Canada. It also provides more leg and foot room than most boats in that size range. Check it out.
I like the Capella as a great all around
boat. I have the RM 166. I am 6’0",180lbs, with a size 10.5 foot. I have had it out in limited surf, 3-4 footers and it handles very well. It also tracks well for the design. What I like most about it is the strength of the hull versus other plastic boats. It is my choice for an all around boat that will get scratched now and then on rocks or beach launchings.
I have a CD Solstice GTS which is my boat of choice for speed, tracking, and trips.
Jim
give them a spin
Yeah, that sure would be easier. 
I could test 3 for 1/2 the cost of a dry suit. www.MEC.ca didn’t think they would be ordering the Scorpio LV but they have the Capella 160, 166 and Scorpio. No questions asked returns even on special orders too. Maybe I’ll start ordering Nigel Fosters till I find one I like, apparently this would be fine by them!
local dealer
claims to sell Necky, CD, Riot, Perception, Ocean Kayak, WS and Delta. He pushes Delta and has a many CD rudder boats, no brit/greenland. The rest are there in more or less in name only, WS Pungo or 2. Only one exception I learned about today, there’s a story for another day.
I was interested in the Chatham, spoke to two necky dealers. Both have comp Lookshas on order but no Chathams. Chatham is the only necky boat I have any interest in.
Avocet “froggy leg position”! I get that exactly and I don’t like it. “The Capella 161 has a straighter and more erect run to the thigh braces” sounds better to me. Also suggested I may be a tad tall for the Avocet. Interesting remarks, thanks
confused here
I was under the impression the Capella’s were bigger in the cockpit area then the Avocet. See tvcrider’s comments above, for example.
Avocet-Romany-Tempest 165
I recently test paddled and narrowed down my choice to these three, but in composite. For the best trade-off of good tracking and turning, I liked the Tempest best. Leaking Kayak sport hatches killed that choice. I liked the Romany best for feeling like I could edge it immensely and control it best. But a mediocre looking layup and poor seat killed that choice. While I felt the Avocet was fairly comparable to these two but did not boast anything particularly special, I ended up buying that boat because the Valley layup, hatches, and seat were perfect for me. I wouldn't mind having all three though.
depends
Cap 160 RM does not feel that roomy. Judging by the skirt, cockpit is comparable to Avocet. I think the seat contributes to the difference - my Avocet has foam seat, really low profile. Capella has raised seat + seat pad. The front edge is raised as well. Would be interesting to try foam seat in the Capella.
Capella 166 RM definitely has bigger cockpit than Avocet.
I have a Capella RM165, a Foster Shadow
and I used to own a CD Gulfstream. I find that the Capella is an extremely stable boat in rough water that is extremely maneuverable and with a little skeg will track like it’s on rails.
It surfs and handles following seas much better than the Gulfstream but not as well as the Foster. The Capella is faster than the Gulfstream but not as fast as the Shadow. Comfort is relative in all three as they are all comfortable boats but different. If you like the Capella, go for it.
Unsure?
I demoed the Capella 160 RM twice last year, so I have put some time in it.
The cockpit opening of the P&H 160 RM is larger than that of the Avocet RM. The foredeck is also higher than the Avocet's. I had to put my knees in quite a splayed position to reach the knee/thigh hooks.
Yes, the Capella's seat might have been a contributing factor. I would nearly come out of the boat when rolling it I had great trouble maintaining 5 points of contact. I was offered very competitive price on the 160 RM, but I opted for the much better fit (for me) of the Avocet RM.
Sidebar: The individual who eventually purchased the 160 RM tried to sell the boat after using it for just a month. Asking price was $699! They found the cockpit too large.
bizzare
I’ll have to try sitting in Cap 160RM to refresh my memories. Was this a newer model?
Yep, 2006
I just dug out the sales offer from the EMS store manager (Model Year: 2006). The second 160 RM I demoed was also a 2006.
I believe someone did tell me that the newer 160 RM is a bit different than the original poly Capella (i.e. larger cockpit). I think the initial plastic Capella called the Capella RM (no number).
One overall issue with the 'Capella' is which model do you have? Six or seven years ago P&H simply called the boat 'the Capella'. P&H has repeated tweaked the original hull quite a bit, creating a host of variants. Your 'Capella' may very well not be the same as the two I demoed. Sort of like comparing the proverbial apples and oranges. ;-)
seat placement and "stuff"
djlewis & bignate, Thanks for your sound advice, I know I should “paddle the boat” , but I was hoping I might get away with skipping that step by limiting my choices to somewhat legendary boats. It’s looking more and more like that’s a very poor idea. 
suiram, I understand that Mariner’s boats had a seat that could be adjusted back and forth while underway. Seems like a very smart idea to me, I suppose that if the seat and back are separate that might be a problem. I understand Sterling’s Kayaks seats are velcroed to the hull and are adjustable back and forth but not while underway, nice idea but I doubt velcro would stick to a poly hull.
who knows
There are some new epoxies that are promised to stick to anything.
http://www.westsystem.com/ewmag/25/pdf/G-flex_Epoxy.pdf
Capella
I’m about your size, and the Capella RM was just about the perfect boat. Somehow (probably reading this board) I got the silly idea I just had to have a fiberglass boat, and have owned a Capella 163 for about two years. It is a great boat, but for the type of trips I do along the Texas gulf coast, I could have saved a bunch of money and been perfectly happy with the RM.
Valley and NDK are excellent boats, I could have bought any of the three, the Capella just fit a little better.
size
size will determine a lot given your height. Avocet may be tight. Capellas come in a few different sizes…may be a good bet.
I like the fit of the Romany S…I am only 5’8 but weigh 200 pounds so my thighs are a bit bigger.
Your weight says you are pretty slender, but have some pretty long legs.
I think fit will be the most important factor for you.
Matt