Absolutely no need for anything over 50lbs for bow fishing in a compound. It's actually more of a hassle.
One thing about bowfishing is that there are no umbrella "absolutes." There are many times I will "absolutely" NOT shoot less than 50 lbs, and others in which I want at least 60 lbs. Draw weight is best determined by the conditions, including the fish you are shooting. Shooting little gar and carp at the surface is one thing. Shooting a 70 lb buffalo five feet down is another. And, shooting carp on the bottom in crystal clear water 8 feet deep is a whole nother deal.
For most shooting in MO, I use about 40 lbs, but I usually pass on the little fish.
On the subject of snap shooting and quickness...I will go up against anyone on shot quickness and I prefer compounds with let-off. Any bow can be shot at any point in the draw cycle independent of let-off. It's all about what you are used to and prefer, and then how much or little you are out shooting.
Here is a fish that I shot using about 62 lbs on, that was in 3-4 feet of water when I shot it.