It all really depends on what they are and what kind of machine you're running. I personally find auto-updaters to be pigs, especially the ones that work totally in the background, but my non-gaming machine is just a 512 RAM 1.8ghz box. When I dump those six processes it's not really their idle load I'm worried about, it's preventing them from deciding to do something while I'm working. If you're running a higher end box you might not notice when some service decides to do that vital bit of maintainence.