There are some real problems that need addressing,Not sure if everybody is suffering from this but Hit detection I totally out,Sometimes I can unload a whole clip on somebody and they don't die then I get hit twice and I'm dead had it loads of times last night.
Another thing that alot of people seem to be getting is the Servers,Quite often you get a server with everybody on one red bar except for one person on each team leaving everybody lagging out,Shooting somebody becomes pretty much impossible as one min they are in your sights and the next they have lagged and appear 3 ft in front of you.
Also I guess it's back to hit detection again but last night I got hit by a bloke throwing a pole at me,When I watched the reply of it the pole he threw was no where near me yet I still died.
All in all though I'm enjoying the game but really hope they can fix these issues,Although I'm not holding my breath.

Probably not so much hit detection as it is the pitfalls of non-dedicated servers. You hop on to a host that has poor connection quality or someone joins with poor quality, and it makes it almost unplayable. Its a shame, but its most cost effective for developers. It's rare you see dedicated servers on console, the ONLY instance I can think of off the top of my head is Battlefield 3.

It just is really annoying as I have a pretty good connection at 60mb download,15ms ping so to be thrown in a server that's awful is a total pain,A server browser would make things so much easier at least so you can pick one from your region and give yourself a chance of a better game.

A server browser doesnt make much sense though for client hosted servers, and also, the fact that there is no variation in the server settings. They'd be switching too frequently. What instead should happen is if there is a single player whos connection is really ruining the latency for others, it should auto-kick them from that server after 30 seconds or so. Either that, or better regional matchmaking.