When we dropped one controller off nights for a month last year we found when we weren't on nights we would be working 6 on, 2 off, 1 on, 1 off before coming back for the 6 on. This has always been the case with the non nightshift cycle, but I agree with Chimaera - it feels like you have less time off. That said, we must get more days off than the majority of other professions so I can't complain too much!!
-HD-