I should say first that we've only had our flat-coated retriever groomed here once. (However, we take her every week for Adventure Park).
They did a great job with the grooming (just a neaten, not a full groom), and they give them breaks throughout so they don't get too stressed. You can leave them the whole day if need be, so it doubles as day care.
I'll put in a plug for Adventure Park too -- Nox is always excited when we pull up there in the mornings. They take the dogs to a 4 acre fenced-in park, where they play for a few hours before getting cleaned-up and returned for a rest until you pick them up. You can read all about it on their site: