I went into the dealership as I was given several problem codes from a diagnosis from an independent mechanic, who did not give me a complete diagnosis on 5/13/15, and offered speculative solutions for the problem which did not sit well with me.
The people at John Kohl were very cooperative with the information that I gave them, and explained fully what the possibilities were from the information that I gave them. and were able to locate the problems quickly and without a lot of speculation, and proceeded to repair the problem in less than one hour.
My only problem is that when their mechanic talked to me about additional work that needed to be done on the vehicle, it wasn't stated that this matter was on a recall notice (which I hadn't received notice on). However, this may be as a result of this being car that was not bought from a GM dealership as a used vehicle; although my vehicle is in their system as having been brought in periodically for repair work.
Overall, I enjoy going to the John Kohl. The owner of the dealership, Ben Kohl (the son of John Kohl) is a very friendly and approachable man, as are the people in the service center (Mgr. Ken Kruse). They listen well, and get reliable people to work for them in the service area. The assistant service manager (Rocky) is new, but appears to know what he's doing. They also have a new parts person, who seems knowledgeable in the few times that I've met with him. This is why I consider them, overall, well above average on the overall scale. One of the few drawbacks that I've found with them is that they do seem to have a lot of personnel turnover, for whatever reason.