As others have suggested. I think this will be a very useful post for Porsche owner to learn about their experience with each individual dealership. This is for SERVICE only (not sales). I will start by my experience

State- CA. Southern California area

Mckenna Porsche- Been taking my 987.2S there for service for the past 5 years and they have been very reasonable. I called around for a price quote on the PDK fluid change when the car hit the 6 year mark as recommended. Their quote was $550 (which actually end up being a little less than that) while others such as Long Beach and LA downtown was around $700, Riverside Walters was $650. and Newport was close to $1,000 (gotta be the OC premium). Loaner vehicle was provided. They used to provide full valet service (aka flat bed your vehicle and drop off a loaner for you) if you have establish a history with them. But recently that changed to only vehicle purchased from them. Although a porsche loaner will still be provided.

So far I have been very pleased with their service as well. The SA that I have been working with is very knowledgable. My 991S is CPOed and I have no issues with warranty repairs so far (ie both interior door panel replaced and a few other minor things)

On my 987.2 the HPFP failed within a year after it was replaced under recall by Newport Porsche. The car was towed in and everything was covered under the factory parts warranty of 1 year 12k miles with no issue. (Although i did buy an ext warranty with them after that incident....the HPFP with parts and labor was about $2000)

both the 987.2 and the 991S was not bought from them.

Havent had any other service experiences with other Porache dealership in the area except a PPI done by Newport Porsche which they were very derailed...but expensive.....