Are you saying
that even when your paddling skills improved the kayak continued to drift or yaw excessively, to the point that it couldn’t be easily corrected by adapting your stroke? That really surprises me.
excessive weathercocking?
I really don’t know what excessive drifting in a stiff breeze off the stern is. I do the leaning thing with corrective paddling to keep it straignt. I did have the opportunity to try out the boat with the rudder this morning in 15 to 20 mph breeze and 1-2 foot chop and the boat is awesome in these conditions as far a s stability is concerned and with the ruder I dont have to fight it.Isuppose a more skilled paddler would keep it straight but I just dont feel like fighting it so and as I said I am fashioning a sail for it so the rudder will be be necesary. saying all that last night the lake was glass and I felt no need to deploy the rudder to keep it tracking straight.Seems to be more efficient without skeg or ruddder when paddling either directly into the wind or in calm conditions.
SImplified
You’ll find in general longer kayaks have more glide. It means less effort to get where you’re going. You don’t need to paddle at top speed to take advantage of it (but the faster you paddle the more the difference in hull lengths becomes apparent).
Kayak length is only one factor in a kayaks speed and efficiency.
Thanks for the clarification
I understand what you’re saying. It doesn’t sound unusual. Yes, a skeg will noticeably slow you down so using your paddling technique to stay on course is better. But as you point out, you don’t want to be fighting wind or waves all day, either. In that sense, a longer kayak would serve you better.
Love my Delta 17
I’m still pretty much a novice, am going into my third season of regular paddling. I’m 56, for what that’s worth.
I went from a Perception Carolina 12 to the Delta 17 Expedition, and it’s the best money I ever spent (and no, I’m not a shill for the company 
I’m 6’, around 200 lb, and the boat fits me really well. I did install the ‘hip kit’ for a snugger fit. Lots of room for my knees with the slightly higher deck on the Expedition.
Initial and secondary stability are both excellent. I can carve it over to about 45 degrees and still feel quite in control. Glide is good, and the skeg does a good job in the wind.
I’d feel quite comfortable letting a total beginner use this boat.
And the storage is amazing