I suppose it depends on the contract and more importantly, what base you're at.
In some of the bases there are very few if any overnights and the schedules are ok.
Based in Tianjin there are a lot of overnights in sub standard hotels and generally the airline will try to squeeze as much flying into your schedule as the CAAC will legally allow. Because you are rarely on time you will almost always fly even more than that.
Typically you would go out for 3 to 5 nights at a time and then fly a couple long days from home base. Vacation is important here because this plane will keep you insanely busy.