Purchased out Terrain 2 years ago. Though there have been some issues with part failures ( GM electronic issues, not dealer issues ), we always have had friendly, thorough and detailed service, and a "know you when you come in the door" presentation. Some responses to inquiries ,that I've regarded as a bit vague, have always resulted in much more detailed and knowledgeable responses, and have been known to invite me to talk with the mechanic ( Are they still called that?) for complete input. Never a confrontational experience, and always a satisfaction follow-up.
Obviously every repair shop will try to emulate this service, and I know one that does a good job, but on a newer vehicle, I prefer to keep it all OEM parts and maintenance. The G.M. tech's are trained to know your vehicle inside and out. I work in a primarily automotive precision tool and die plant. I have stopped buying aftermarket parts. There are reasons that OEM pats are more expensive, and on a vehicle with a lot of life left in it, they ARE a good investment. I checked only three stars on the price rating below, because if we checked 5 stars, GM wouldn't try to keep prices competitive.
Is one dealership any different than another? I say yes. Each has subtle differences. We keep coming back to John Bear in New Hamburg for those subtle differences. It's not the closest for us by far. It's the best in our opinion.