True fact: Some of my cow-orkers appear to have adopted this very policy.
The downside is that their computers are ALWAYS ON. 
 Due to power fluctuations and brownouts in our area, our lab group has been forced to schedule weekend shutdowns of lab systems (a real PITA when testing a rush-rush patch needed before Monday). During one such weekend, I noticed that the lights (and desktop 'puter) in the office of a certain mangler remained on without interruption. 
 AFAIK, based on random samples over >20 hour span.
 I'm just waiting for said mangler to be named divisional D_o_G.