We've been using this company for nearly two years now. They are super-reliable, and if they are going to be even just a few minutes off schedule they will call and let us know. We live just outside their normal service area but they still come out here reliably.
The dogs seem to love them, and they always come back looking and smelling great. They add extra work as needed like when one of ours goes through a shedding fit, or has allergy problems. The people have always been really friendly.
The price is actually a little less than we were paying a chain pet store. The dogs hated going there, and we had to drive to them and wait around for an hour.