I have had a few playthroughs and generally think the hacker is the best, by far. Aside from being powerful, the mechanics of other styles do not work very well. One big issue is that armor is generally worthless as far as protecting you. So any kind of non-stealthy gunner or melee build is going to get into trouble fast.
Sneaking is marginal, at best. Again the problem with any stealth melee is that once you attack someone, you can easily alert all the guards, especially with cameras and all that. It slightly better with silenced weapons, but only a little.
This just leaves hacking which can not only fry people at extreme range, but also turn off cameras and disable security system. It is not that hacking is OP, but more like the other builds turn into exercises in frustration with a lot of safe-scrumming because things can go very wrong, very easily.
I think the fix is greatly improve armor and somewhat improve stealth mechanics.