Pretty much yes.

If your hashrate is unaffected its unlikely that your rig is being affected by tiny amounts of idles. Ignore the "fatigue" guy, sounds like he has some weird problem with his individual setup.

The only problem I'm having with BTCGuild is a slightly overhigh stale share rate. Still floating around 2%, whereas before I used to be at 1/2%. Perhaps its just an inevitable effect of higher difficulty I dunno.