Yes. I can no longer access my league stats and although my favorite game is 9B (fast and loose) I'm pretty sure my 8B win percentage is higher than my 9B win percentage. I guarantee my current 8B B&R percentage is higher than my current 9B B&R percentage. Truth be told, I bet most people who are proficient at playing pool have a higher 8B win percentage than their 9B win percentage (rotation in general and all other things being equal - mainly opponent's ability). Simply put, it's an easier game. 8B is a game of shot selection while 9B is a game of shot execution. Chances are, you'll make better decisions (again, must be a proficient player) over the long run than better shots. As long as you can pick the right shots in 8B (and can pocket balls, i.e proficient) then you'll be OK but in 9B you have to be able to execute said shot and not everyone can do that.
I enjoy 1P and 14.1 but if I'm not dedicated to that particular set I will eventually lose interest and a similar caliber player with better focus will generally get the better of me.