I have to say, I wear Night and Day contacts (did you know the highest prescription they make is -10? Hope I don't get worse!

), but I still take them out every night. I think since they are designed to be slept in (although I think only for 3-4 nights at a time, not 30!

), they let more oxygen into my eyes and I can tolerate them better than regular contacts (I can only wear those for maybe 8 hours at a time). I have bad dry eye problems.
I also clean them every night with a peroxide solution cleaner (Clear Care) - not just plain contact solution. That seems to help too. And if I happen to sleep in them for a night, it's not the end of the world.