I'm currently doing my degree as a mix of online & at campus subjects. I've found you need to be very organised to do online study but you can do the work when works best for you. I ended up doing study at midnight the other night because i was awake & couldn't sleep. My courses aren't "at your own pace" so i cannot comment on those type.

I have had friends who have completed degrees totally online through a university, not open uni but one of the universities that have distance students.