I can't judge the way it''s going on regular fair/realistic modes. All i can say about it is, we have a counter @ ITST mod, Hewitt. He always being considered a good pick though not especially op, and not all people know how to move and position well to play shots early enough to get all benefits of this playstyle. Obviously he has very good returns, but if he doesn't earns ball speed from the opponent shots, then his rough accels are not on par with punchers or power baseliners ones. So in fact he is not a very popular pick, cause this needs some good skills to use him properly, thus, in good hands great results are definitely possible.
On our side, if there is an imbalance , it's the counter stamina management. On our setup (around 70 speed, +26 average stamina gap), Hewitt had to go for a +18 only (-8% stamina gap difference vs. punchers) to get things even enough, or he would outlast any other type of character on the long run. To me it means that, at "equal" stamina loss compared to other styles, the counter is technically, gameplay wise, shot produced wise, balanced enough, and doesn't needs a raw stamina advantage.
Our stats are specific, but my guess is this apect may translate to other stat modes.