KDR, I am a pretty fine shooter both in real life and in video games.  I find that after a few beers, I actually play a little better.  The reason is that I am able to hold off the shot for a fraction of a second longer, which gives me more time to line up the shot.  Basically, I am calmer, and have a greater amount of patience after a few beers.  My reaction time and sight isn't affected to a great degree.