I managed to get some luck and played 2 games of AVP just a while ago.
Really cool game actually, played one match as a Predator and one as a Marine.
Predator is cool, but I found that you depend very heavily on melee combat, there aren't a lot of ranged weapons that I found on the map. Their vision modes are useful, particulalry the Alien finding one, since those guys are sneaky buggers.
The marine feels really different, needing to remember to use Stimpacks, and also to block/melee etc. Vision is really limited, even with the flashlight, so you need to make good use of the motion tracker. Very frightening way to play, it's cool to see the motion tracker going crazy, spin around and have an Alien stalking you.