PS3 MP Impressions:
Couldn't connect initially; tried for 30 minutes or so. I ended up moving to the campaign to make sure it wasn't MY internet that was messed up. When I went back to MP an hour later, I connected right away and had no further problems. Played for 6 hours, give or take, all TDM.
I only played as the scout class, and it was a lot of fun. I liked the highly mobile nature of the class, and once I had the map layouts down, I was able to flank pretty easily. I got up to level 10 before I stopped for the night.
The default control scheme is aggravating because it puts the transform button on your left thumbstick, which I press accidentally a lot. The alternate control scheme maps it to Triangle, which is much better IMO.
Other than using it to get around quickly, I didn't feel like the vehicle form of the scout offered much for combat. It's just got a pretty weak machine gun. The other classes seem to have more useful vehicle forms.
I never experienced lag, but there were a few times I saw the frame rate drop drastically. Overall though, it runs really smooth.
I wish the gunfire felt like it had more impact. When scoped and shooting at people long range, I have trouble telling if I'm even hitting them until they actually die.
The HUD could be better. There are a crap ton of little announcements that pop up as you fight, and it can be distracting in the middle of combat. For example, I might stab someone from stealth and get a message for it being a back-stab, one for the kill itself, one for it being a melee attack, one to announce a kill-streak, one to announce a humiliation, one for being under the effects of a war cry, and one for them being blinded when they died. I would like an option to turn off everything but the actual +50 kill message. On the other hand, your active abilities which are on cool downs barely do anything to announce when they are usable again.
The kill-streaks seem pretty tame overall, but I think it's a good thing, as it keeps the focus on actual combat and gives less incentive to camp in a corner for a kill-streak.
The lack of map variety is going to get old pretty fast. Every level is filled with the same metallic surfaces everywhere you look.
Spawn system is good so far. I never once spawned into gunfire or any other bullshit.
I couldn't find a way to switch which shoulder I was looking over. Am I missing something obvious?
Scientists annoy me. They always seem to drop a sentry and run away at any hint of danger. They also like to lurk above doors in the open areas hoping to ambush people. They're so weak though, that they really just seem like nuisances, rather than actual threats. This might be tinged by my scout-only experience so far. I rarely traveled in the wide open areas without being stealthed at the time. I think the biggest threat to my scout style was soldiers with the EMP shotgun, and the whirlwind melee in enclosed areas.
I barely saw any Leaders being played. It was usually an even mix of the other 3 classes, though.
If anyone has any specific questions, I can try to answer them.
Edit: I also really liked the customization system, though I wish you had some variety of grenades to pick from, rather than being stuck with one type forever.