The biggest things I notice about this game.
If an enemy is behind a wall or truck, you'll be able to see their name in red as if the wall weren't there. This happens during the first frame or two if you manage to put your cursor over their location. I cant screenshot this, since it's only for a brief moment, but I hope this would get patched.
Down time in between rounds for "competitive" modes like bomb missions is a bit long. Not sure if it's intentional or not.
Needs a way to lower the voice that calls your kill/headshot etc. Aside from Master Volume, none of the specific things you can lower seem to affect it. On a side note,
It would be really great if the quality of the other audio resources were increased. I'm using decent headphones, and all the gunshot noises seem to be the same "thump" or "boom" sounds, with the volume magnified much more than they should be to compensate.
Grenades won't throw after you let go of the mouse button. You have to wait until your info reaches the server. It makes jumping and throwing a grenade over a box you're behind tricky. (PLEASE don't mask this with a grenade that renders for local computers, and has no effect on actual grenade location; it's been done before, on really bad games)
There's a post-game load screen, can't possibly imagine why.
My only performance issue came from either mutant mode or recording a movie from the replay editor.
Replay/spectate in first person does not accurately depict the aiming of the user. It seems to lag behind, and the "degrees turned" per second seems to be capped.
Some gameplay balancing issues, mostly that default weapons are useless compared to the available upgrades. I haven't tested this, but actually moving at 130% speed or having 130% effective HP from one item seems a bit much.