Spitfire or Rapidfire
I haven’t paddled either boat, but I have paddled a lot of boats in the very waters the OP describes: Florida springs (my favorites), Florida lakes, and southeastern coastal rivers, estuaries and coastal waters.
Based on the general character of this water, my answer would be whichever boat is faster and holds a line better. You need speed to paddle upstream in the springs and rivers, if you do round trips as I do.
You don’t need uber-maneuverability on those waters. A 14-15 foot boat than can be leaned is plenty maneuverable. This isn’t the oxbending, beaver dammed Chubb in Lake Placid … though on a really small and skinny slalom spring run such as Juniper or Rock Creek in Florida, I would highly prefer the vertical, close-to-the-gunwale elegance of a single blade canoe paddle rather than a double bladed, branch-entangling clunker.
I paddle those very same high magnitude springs, rivers, estuaries and coastal waters – but not Juniper-Rock Creek stuff – in a 22’ solo outrigger canoe, which can’t turn at all.
Can’t speak to fishing from these or any boats. Not my interest. My perspective is purely from the paddling performance standpoint.
Get the longer and faster boat, which should be able to carry more gear, junk and creatures, and to power upstream easier. It would be even more valuable to my paddling style if it could be set up for both sitting on the bottom and kneeling with a single blade.
Then, if you could also add a retractable rudder with foot controls, you could even paddle upstream on the Chubb or Alafia – or into the wind – single bladed, without getting knocked off line and laboring with the sweep strokes of Sisyphus.
Speed is related to the size of the
paddler.
Smaller boats are more efficient for the smaller paddler as there is less skin friction.
Longer boats are often a waste because smaller paddlers cannot generate sustained power to maximize the boats potential.
Shorter boats accelerate faster…perhaps an issue on turny rivers.
Don’t buy more boat than you need.
I paddled Spit several times and Rapid several times before going off to think about it. I got Rapid because my outings in that boat are not typically day trips. I needed the volume for gear.
Neither would find any advantage from a rudder. DY has made both quite wind friendly and Rapid keeps a course even on that dreaded rear quarter wind.
Rapid at least is available in a kneeling setup. You must indicate that at time of order…no retrofits.
And if you go with a low or med or high seat on the bottom Marc Ornstein at Dog Paddle makes single sticks that are short shafted, so you can single blade away sitting.
2nd the wind worthiness of the RF.
I got caught in a blow that literally slapped the boat sideways;no weathercocking.
Was on the ICW with a 30mph following wind,fast enough I did not need to paddle.I used the paddle for a rudder.
My only basis for comparison is a Wenonah Voyager. That sidewind would have been a battle to overcome and I would probably have lost. Tailwind-no problem.
Rudder and kneeling seat
My comment about putting a rudder on a PB Fire boat was mostly facetious. It would ruin the very character of that boat.
However, as a general principle, there is nothing better than a rudder on a paddle craft to fight wind and hold a line. It can also help holding a line when going upstream against stiff current.
If you want to be able to sit on the bottom and also kneel, it is most convenient if the kneeling seat-thwart is made so that it can be removed and replaced within seconds. That way, you can change positions on the fly without getting out of the boat.