No, not seen anything like you mention. Occasionally it feels as if my character isn't running or moving at full speed tho, or wont run for as long as he should. I'm sure that's more to do with the lobby being laggy than any hacks.
I did once get into a Domination game and as soon as the round began a player pulled out a Stealth chopper and Lodestar before he had any points or kills on the board. I think similar instances were mentioned here a while back too.
Other than that one time this game is pretty clean.