Never paddled a Prism --

I'd guess you were way bow heavy when you kneeled in front of the seat (don't see how you couldn't be)- a bow heavy boat will act like you described, veering off course and being stubborn to get back on.  That would probably account for some lack of glide also - pushing a big bow wake.  

Much of what you described is common/typical with any solo boat - I have never yet heard of anyone not having more issue with a tailwind than a headwind.  Wind affects a lighter boatload more than it affects a heavier load - that alone will account for some of the difference between the Sawyer and the Wen, and it sounds like this trip you went quite a bit lighter than your normal load.  I retrim my boats frequently for changing conditions, even change in wind intensity - there is not one setup that works for all conditions, which is why I use two packs.

Did you have a striaght shaft paddle with you ?  I'd recommend trying that next time, using a "C" stroke in place of hit and switch - you'd probably have less of an issue with not being able to stay on the same side for a long time, and I'd try trimming a little bit bow light, rather than level.


p.s. - sounds like you might be comeing down with "the itch" - probably won't be a better time to find a good used solo cheap with the economy being what it is.  Just saw an 18 foot Sawyer  in escellent condition selling for $400 - I've been seeing lots of good boat deals lately on Craig's List, just wishing I had room somewhere for more than 5.  Wouldn't surprise me to see a nice solo going for four or five hundred.  IF you think ten pounds lighter is nice, try 15 pounds lighter!  My Indy only weighs 45lbs, but there is a huge difference between it and the 29# Merlin