I'm glad that the forums decided to break as I went to preview my post and it deleted everything, so now you get the short version.

My specs: http://forum.daow.net/viewtopic.php?f=6&t=4#p79

Game lags seldom, but often; didn't prior to Steam release.

Framerate issues in specific environments.

Sound channels seem limited to 8/16, sounds fail to play a lot.

I don't recall the game having any of these issues in the past (save maybe the FPS issues)

Edit: Video of the sound issue here: https://www.youtube.com/watch?v=n4AjA8Z12B8

Also has a very minor lag issue displayed, specifically the 3 shot sounds being played, but only 2 firing.