Well let's see, what hours am I getting back? Typically we're looking at the hours between 4 AM and noon the way my schedule is currently constituted, which means that I could either spend that time gaming or pick up a job at Starbucks or a donut shop serving coffee to early risers. Either way, I'm not losing much by sleeping (unless, and this is more intriguing, I wanted to use that time to write and made a commitment to so doing---I could probably land a decent gig.)
If I were in a more typical role, say, the schedule I'm gonna have to keep after college (when my degree will require me to work banker's hours), sleeping from 11 or so at night until 7 in the morning? Nothing's open that late (except casinos around here, and have you ever been in a casino on the graveyard shift? Christ, it's like taking the Wild Wasteland trait) and there's really nothing to do except either take up a self-employed second career (writing, as previously mentioned, which these days I don't do much of because my daily commitments totally wreck my creativity and I have to recharge in the evening) or build one hell of a Sims 3 neighborhood.