Kinda depends on what you're fishin for. Being a catfisherman, I'm a believer in a good aluminum deep-V. Just sold my 18' Starcraft that was ideal and spent many hours on the Ohio. Drug in thousands of pounds of fish over the years also. Friend of mine uses the pontoon and does well. Fishes tournaments from the thing and wins often so they do work. Everybody knows if you intend to fish for bass you have to have a low draft surfboard that will run over a hundred mph.
Them bass must be speedy critters.
The barges can put up quite a wake, especially when pushing upriver with a big load but they don't hold a candle to the Delta Queen running wide open, upriver, at 2a.m. when you're anchored just off the channel and half asleep. Makes you appreciate a good deep-V real quick.
Long story short. You can't beat a properly equipped aluminum deep-V with a deep draft for this ole river. You can get by with a 16 footer if you're an experienced boater, but 18 or bigger is exponentially better.