Our son (aged 1) seems to be settling into nursery fairly well, but gets does start to get upset when other parents start picking their children up.
Most days, I think we'll be some of the latest parents to pick up, but on other days, my mother-in-law or husband will probably be able to pick him up a good couple of hours early.
I think that if we have the chance to take him home early, we should, but has anyone else found that being consistent with a pick-up time helps with settling in?