I like the game itself a lot but these problems make it very hard to enjoy it.
Video: I suspect this has to do with my AMD CPU. I read something about that being a known issue at the help center. Just thought I'd bring it up anyway. I get 10-20 fps (the lower end of that all the maps except the subway). Sometimes it keeps locking up for a few seconds at a time for a minute or two, becoming completely unplayable. I have an AMD Athlon 64 FX-62. Which, though not great, if I recall correctly is still above recommended specs. I look forward to the .5 patch.
Audio: Might be related to the CPU thing, but audio is pretty bad. Its muffled, lo-fi. If there was an audio quality option it sounds like its on "Lowest." Sometimes it skips (the sound it might make if my computer froze during gameplay) and comes back, or sometimes it cuts out completely for several seconds. I have on-board 7.1 on a nVidia 590 Sli, with 5.1 Logitech speakers hooked up to it using the latest Realtek HD Audio drivers. This is the only game I have this problem with.
Pings: I think everyone who plays knows this, but pings are bad. I suspect its just a case of not having servers spread over a wide enough area yet, but I thought I'd bring it up.