Sorry for the late chime in. Running LPx on HD card and Avid HD i/o (under core audio)
16 inputs and 16 outputs seen by Logic.
So far so good. I usually use Logic for my work, but my freelance engineers work on Pro Tools, and other studios sometimes want PT sessions.
At home I still run my trusty Fireface 800 with my MacBook pro. Using a thunderbolt to Firewire adapter to connect to it, no problems either.
Best of luck