...it'd be easier to answer your question about which boat if you knew which version of the Fun you're talking about. The newer Funs (the '07-'09 version & the '10 version) are great downriver AND really good playboats. Loose hull, able to do plenty of hole/wave moves. That said, I haven't actually paddled the newest Fun, but it looks much more playable than the '07-09 version (which I have) and from the reviews I've seen it is.

If it's an older fun (pre-'07) then it isn't a great playboat - so if playing is an important factor for you, then pre-07 Fun isn't the boat for you.