The hit detection's really iffy. There have been several instances where I get around a corner and die from shots on the other side of it. It's not like a small lag type of thing either, it's getting 20 feet down and dying after the fact. Given that no other game I've played has given me connection-based fits in the past, I can't really blame it on my Internet. The whole concept they touted about balanced matchmaking is terrible, because it's nothing close to that. Winning Attrition games by 100+ points or losing Pilot Hunter ones by 20+ have been fairly commonplace. The Jump Kick hit detection is about as-dependable as Call of Duty's knifing ones. That might be a bit harsh, it's not THAT bad, but there are too many times I'm on the giving and receiving end of awkwardly-placed kicks.
Then, there was this one time, and it still bothers me...
I was on the ground, some guy was on a roof. I was looking straight at him and was about to turn behind a wall before he could shoot me. I noticed he was looking maybe 45 degrees away from me, and he started shooting. I figured he was shooting elsewhere, so I'd try to kill him before he noticed me. Instead, in the second I made that decision, the bullets shooting from his gun--again, 45 degrees or so away from me--killed me. Apparently, he HAD been looking at me and shooting me, even though what I saw on my screen was bullets going off in a totally-different direction. Given that this game came from the same people who made MW2, I can't say I'm surprised. In that game, I was once standing on a roof, someone threw a knife into the face of the building, maybe 5 feet below me. Of course, through some force of magic, that knife killed me. It was the same feeling of helpless confusion.
I like the game, it just needs SO much polish. The biggest gripe I probably have it how bad the campaign was. They need to either make a single-player experience or stop trying to have a story, because that story wasn't worth following.