Overall we like the way it handles. It's fairly fast for the length and the keel, but also it tracks well. Stability is decent and it's pretty maneuverable. We haven't done much river work with the boat - I don't want to break the boat...
We did a shorter trip with it last weekend with two big packs (and my 215 lb. self in the bow). I wouldn't put much more in it, but it carried us fine with stability and freeboard and didn't take on much spray in 2ft waves. The rental boats were Scott Prospectors and ours was noticeably faster.
We're interested in buying our first boat and have been demo'ing boats. We're interested in something a bit larger for bringing our dog along and for bigger trips. There are faster and nicer-paddling designs out there, but the Scott is still a really nice and versatile boat. I think it's marketed as a lower-capacity beginner's boat and that's fair. The fiberglass version is also pretty reasonably priced.
Just get a deep dish yoke if you portage! The factory one wasn't friendly. The best $50 you'll spend, guaranteed. The ~60lb fiberglass model wasn't terrible to carry.