Read reviews for the RF I by Zoik Inflatables as submitted by your fellow paddlers. All of the reviews are created and written by paddlers like you, so be sure to submit your own review and be part of the community!
The kayak itself has a pretty unique floor design, the whole thing is arched up about 5 to 6 inches above the bottom of the tubes, so it makes it very cataraft like in handling. I find this works very well and my butt stays nice and dry.
I've put about 50 river miles on it so far, mostly on class II/III water and one class IV run. In all cases, I was very stable, but did flip on the IV (my fault, not boats!). The kayak bails really well. I haven't done any flat water and probably won't, its not designed for it, and I'm sure it won't perform well there.
Overall, extremely happy with the kayak, it's generous 5-year warranty and excellent performance. BTW, this is a NON-bladder style, which I now prefer. The AIRE and Advanced Elements boats use bladders, which work fine, but are a real pain to clean and dry out.