I'll share my recent experience, which I think demonstrates both the bad and the good, though more of the good, and I'm willing to chalk up the bad to the service center having more work than it can handle.
The Friday before Thanksgiving--November 18--something went horribly wrong with my lift gate, and it simply would not open. I'll skip all the details, as many of them are included in my post in the lift gate thread, but the bottom line is that the actuator had gone bad, and there was absolutely nothing I could do to open the lift gate. In this situation, even the emergency release does not work. The car thought the lift gate was open, which meant that the doors could not be locked, rendering the car essentially undriveable except for trips where we would not be leaving the car unattended.
I had started by calling the roadside assistance line, as I thought there may be a way to get the lift gate open. There wasn't, and the result of that call was that someone from my service center--Mt Kisco--would call me the following day--Saturday. When no one had called by late Saturday afternoon, I called them. They were apologetic, knew of the issue, and said someone would call me on Monday. I did receive that call, and then several others that week. The result--and this is the bad part--was that it took until Wednesday of the following week--November 30--twelve days--before they were able to come pick up my car and bring me a loaner.
I chalk this up to the service center being overworked. Initially they had been talking about sending a ranger to fix the liftgate, as I am over 200 miles from the service center. They then realized that my car was within about 1000 miles of being due for its 3-year, 37,500 mile service, and asked if I'd like to have them bring the car in for that instead of sending a ranger out. That was fine with me. So the Wednesday after Thanksgiving--November 30--they brought me a loaner, and I had my repaired and serviced car back that Friday, December 2. So that is part of the good--the service center worked very expeditiously once they had my car.
Here's some more good, at least as far as the service center is concerned: they replaced my 12V battery even though it had not caused me any noticeable problems. (From a manufacturing standpoint this is not great, as I am now on my third 12V battery in less than two years.) On the upside again, both replacements were made without me knowing there was an issue, so Tesla definitely deserves kudos for that.
The service center also discovered an issue I was unaware of concerning a control arm, and replaced it.
They also mounted my snow tires (which were on wheels). (The service agreement I purchased includes tire rotation.)
And going a bit above and beyond, I had asked if they could possibly get the car its state inspection, which was due in December. (The work was being done on the car December 1.) I made this request because when I got the car inspected on my own a year ago I fear the place I took it to raised the car a bit without using the correct jack points, even though I had brought them instructions. So I was trying to avoid that this year if I could, and I knew that Tesla had taken care of the initial inspection, so I hoped it would not be too much trouble for them to do it again. I completely expected to pay the inspection fee of $10 if they could accomplish this.
Well, they --DID-- get the car inspected for me, and when I called to see if I could pay the $10, they would not take my money.
So I guess what I am saying is that as far as I am concerned, using my most recent experience to judge, the quality of the service itself has not decreased. The amount of time it took to get the service could have been better, but I do not blame that in any way on the service center or its employees, but rather on Tesla, as they simply need to increase service center capacity faster than they have been.
