I kept a pike once from ice fishing as a kid and I pretty much ruined it trying to clean it. This was the days before YouTube and I was trying to figure it out myself on the fly. Not my proudest moment. That being said, it tasted alright cooked up as a fish taco, but I'll admit it wasn't the best-tasting fish for that and I decided it wasn't worth it to try and keep any others after that.
Why are you supposed to throw the bigger cats back? Is that just the fishery rule to encourage a healthy population? I've never been particularly fond of catfish which is unfortunate as we have them in absolute abundance here in Texas. At the lake five minutes from my house, I believe the daily limit is 25 channel cats with no minimum length (although there is a cap on the number of fish over 20 or 24 inches you can possess, but I don't remember the specifics). Flathead cats have a minimum length, but I don't even know what it is since, again, not a huge fan of catfish. I just go for the striped bass and crappie.