Unless you're shooting really good distances, I dont think itd make much of a difference. And, since you have to train yourself to hold under the fish you are shooting at, all method of aiming you are used to using kinda goes out the window.
I bowfish with 45lb and 55lb recurves, as well as a 54lb longbow, and I see no difference in arrow flight with the uncut fish arrow. But, I never need to take shots more than 10 yards while bowfishing, either.
Just my thoughts, though...someone else could have different experiences.