I also guided fly fishing for many years. I’m with @king fisher, it is most effective in small streams for fish that are eating bugs. I don’t participate much anymore but I can still wax them in a tiny mountain stream if I need to. I’ve got a good friend that guides smallmouth floats and he can really catch a lot of nice fish, river smallies are in tune to the drift and it can be extremely effective. Personally when it comes to bass, I’d rather jack em and fight em on conventional gear