Downtime, yes, but probably not sleep. From what I understand, if you're only going to spend part of your day under gravity, to maintain health you need to spend that time working your bones and muscles. You'll want stuff where people are active, such as gyms, maybe a jogging track on larger decks, lounges, bars, stuff like that. Actual unconsciousness time does nothing for you in this regard, so you might as well do that in zero G. I suspect only the largest stations actually put people's quarters on the grav deck.