Overall my experience with Tesla has been generally above that of all other car dealerships in my area. Never being sold service I don't need during a warranty visit is just unheard of.
Service Center policies are inconsistent, and that probably will continue. That was expected when Tesla was a new production car company 2008-2012. Now people question it, after 9 years of car production. "Fully loaded Loaner cars" are the first deviation from Tesla's service policy website. Some folks do get fully loaded loaners, some folks get base model loaners, some get ICE rental cars, some don't get a loaner at all. Some folks had to pay for ranger service, some didn't. Some folks got valet service, others had to pay. Some folks get free washes and waxes, some vehicles never get a wash at all. All dependent on the service center, not corporate policy. Goodwill is the line item for when Tesla goes above and beyond your contract. Some receive more "goodwill" than others which may be making some people feel irritated on the forums.
Personally I've had about 7 loaner cars. At first they would valet a base model S to my vehicles location. SC had time to investigate and repair all sorts of issues I had not even discovered yet. Then the SC began to charge for valet, still the base model loaners. Then when the X's came out, the valet and fully loaded were reserved for the X customers. SC stopped having time to do extra above and beyond proactive work on S's. The X's had so many initial quality issues, they were backing up in the service schedule queue. It wasn't until the SC accidentally totaled my vehicle that I was provided an older yet fully loaded loaner vehicle. They did let me keep the loaner for 3 months while my X was being built. I disliked the loaners snow tires during the summer, it rode really harsh. Once I got my X replacement for the damaged S, and had the X in for service, no more free valet for the X's but I was given the fully loaded X loaner. Now at the annual service, they no longer have loaners, but can again valet with an ICE rental car if I choose.
Over the course of 8 visits, I got 1 wash, and quite a few promises to wash/wax it "next time". For people this matters to, just get a car wash membership somewhere. I'd rather not have someone else scratch my paint and try to buff it out.
If I had to make one small improvement that's an easy policy change. All owners with annual service plans are in the computer, assigned an initial service center. Tesla also has access to the odometer of every vehicle, and could proactively have an intern reach out and schedule those annual visits, without having to make the customers call in and schedule. That would better balance the SC workload between annual visits, and warranty repairs.