jkelly,
I've been careful about sleep mode on my macs since switching from OS9 to OSX. I'm not saying I don't put my machines to sleep - the opposite, I am mainly on a portable and have to put it to sleep a dozen times a day for travel, etc. It's just that I advocate keeping sleep under manual control so you're sure there's nothing funky going on. Even with being careful, the apple laptops sometimes exhibit strange behavior in waking from sleep which, while not necessarily VW related, can really effect your work if you cannot successfully wake the machine. In realty, the unix core of OSX is designed to stay on 24/7 and some system relevant tasks take place during the late night hours when your machine is theoretically not in use - if it's in Sleep these maintenance tasks cannot happen.
Now whether this goes counter to any pro-environmental policy is not for me to say...