Porsche dealership service definitely has two levels..

[Nine8Six]

The Pealership in Shanghai have very (very) high cleanness standards. Tools, garage, docs, computers, all is surgically cleaned regularly. I know, I have the privilege to know someone there that allows me to visually assist the mechanic when my car is on their lift. Floors are impeccable and cleaned every 15min on average. Spotless clean and professional.

Thinking of it that might be the main factor why one left his messy and blobby brake job in this customer's wheel.... instead of onto his nice white/red floor area

[NewArt]

I have yet to go to the dealer for service but I will go for parts sometimes. Living in Canada means paying through the nose for shipping/duties/brokerage fees for a $100 part which one might order through ECS, or Pelican, or other US based suppliers. The parts guys at Prestige Porsche are helpful and friendly, but really on the older cars, it's just a matter of $ and sense!

[BrokenLinkage]

Just back from the dealership this am. Had an oil change coupon for $91.xx, so I figured what the heck, setting up and doing it costs me at least 90min and the materials cost me about $56-65, so $27 for 1.5 hr of my time (not counting getting sweaty/greasy and changing clothes) seemed like a deal.

It took them about the same 90 min. The bill was $120.xx by the time they added $19 for "shop supplies" (expensive porche oil rags?) and tax, but I didn't protest the bait and swap price since they threw in a basic exterior wash. The service cover for the seat had been loosely refolded on the passenger seat, suggesting it had been used.

Got to my next destination and found a new small glob of black stuff on the driver side door carpet. It looked wet, but when I went to blot it with a napkin, it just smeared.
So, after my first appointment, I went back. The service mgr came out, looked, called to the back to get it cleaned, then addressed it himself with a towel and his secret cleaning weapon (eyeglass cleaner). Good result & I was on my way again.

So, in summary
price A-
promptness A
cleanliness C
professionalism/courtesy A+

Doubt would be any different for a 911 of same vintage.