Babylove; I am sorry you had a bad experience with child care. I am glad that you chose not to bring your child anymore, since obviously the trust was gone (or there never was any) and that is CRUCIAL to a good parent-caregiver relationship. Better luck at the next place!!
Now, if I can just weigh in on the debate re: diaper changes.
I completely judge the necessity of changes on the individual child. I have one child that honest to goodness does not require a change until after lunch, before nap. He arrives around 8, so that means over 4 hours in one diaper. But if I change him mid-morning, I am literally changing a dry and clean bum. That seems wasteful to me? Most of the other kids seem to need a change mid-morning, then after naptime, and maybe one more before home time. This, of course, excludes any poopy bums. Those get changed immediately.
My point is; I change bums based on need, not the clock.