The feats are fine in this game but they do come at a slow rate that I think is dumb because you have to gain levels to unlock each feat then stand still in a game for them to activate. It's to much work to use them in game. I do like the cooldown after you use a feat though. I rarely get to my 3rd feat.
I see the feats as Killstreaks, which I believe is a good balancing choice. What I don't like is:
They don't teach you how to use feats.
They don't mention feats majorly for a while.
They are very obscurely placed at the bottom of the screen and you have to somehow remember what the small signs did and look away from your screen as a Berserker is leaping towards you.
I haven't had any problems with the feats. I agree that they come somewhat slowly while in game, but I haven't really had any issues unlocking the first three feats on a consistent basis. I have only had the opportunity to unlock the last feat a few times, but that feat is generally pretty powerful so I don't really have any issue with that either.