I'm an old rafter from the '70's and still have my old Campways Shoshone raft - 16 feet long. I know that there is better stuff out there, but my old raft still works fine. With a little forethought to packing, you can put a lot of stuf in a raft. I've twice done the Main Salmon, and continued down the Lower Salmon to Heller Bar, taking a full two weeks to do it. It's been great on the Owyhee, Deschutes, Utah's Green, etc.

Rafts are the only way to go for really long trips, or big water like Hell's Canyon. I took my driftboat down the Middle Fork a few years ago, and would MUCH rather have had my raft.

Rafts respond a little slower, but are so forgiving. They're a little harder to fish out of, I think.

If you're looking at a serious expedition type raft, I think that the NRS 16 footer would be hard to beat.