I had a Dave Scadden which has similar components. I think it is well made. My only comment is to add some type of leash to the pins that can come out. The leash/string will make the pins easier to find.

I believe the Fishcat is probably one of the best boats in that price range. Class III or IV in a $500 boat seems riskly to me. Yes, the tubes are rated at III, but realistically is the boat for fishing or whitewater. You shouldn't be running III or IV by yourself, so I hope you have a partner.

If you want to run serious whitewater, I think it is too small. Most the normal fishing rivers are not III or IV, so it should work just fine.