I've used it on Mac before, I know I got up to at least 720p resolution but it will have latency. If you want less latency, use a capture card like the Matrox MXO2 or Blackmagic Intensity or Decklink in conjunction with a camera feeding into the capture card.
iam using the c920 from logitech. Its a great camera with full hd in resolume and full remote controll like iso, shutter, white balance and focus. The latenzy is the same like a blackmagic capture card (160ms). I dont know about the matrox exept that they are expensive.
I have used the Microsoft LifeCam HD-6000 on a Mac Mini with no issues whatsoever. It was completely plug and play, and the camera appeared in the Sources menu. Latency was undetectable, identical to BMD cards. And I was just messing around on a comp with the Intel integrated GPU.
While I was using a 720p model, I *would imagine the 1080p model in the LifeCam series would be just as easy to set up and use. There may be more latency, but probably just 1-2 frames.