I'm just about to start the last leg of my first road trip. Supercharging in Oregon was a breeze, but I had serious problems in Gilroy, only getting 8KW when I was the only car on the entire old half of the SpC. Later the same day the best I could get at Atascadero was 60 Kw. I was wondering if something was wrong with my car. In the NW I always get 120KW for at least most of the charging cycle with tapering over 80% charge. I went to Morro Bay and charged again at the Atascadero SpC the next morning where I peaked at 90Kw.
I have been lucky enough I have never had to plug in at an SpC where I had to use the other half of a pair. Including this trip.
I was lucky enough to meet a Tesla tech at the Menteca SpC yesterday. Interestingly, Tesla is transferring him to the NW soon and he just got back from house hunting in the county where I live. He was replacing the plugs on a couple of the SpCs, but was also asking people about their charge rates. I was only getting about 50Kw initially and he had me move to the other SpC on that pair and I got 120Kw. He took apart the one that was only delivering 50Kw and found a wire that was loose.
I told him about this thread, which my SO found when I was telling her of my woes in Gilroy and Atascadero (my father's internet failed me in Morro Bay so I had no access). He was baffled by some of the stories especially my 8Kw problem at Gilroy, but he did say that the day before (after I had been there) he did a major repair on one of the older SpCs, so I may have gotten the one that needed repair.
On the others being slow he said the California SpCs get some of the heaviest use in the world and many times they don't get a chance to cool down after use. If the unit gets too hot it goes into limiting to save itself. He also said that after a lot of charging cycles the hardware gets degraded from the constant heating up. The good news is they are designed to still work as they degrade, but the bad news is a lot of California SpCs get a lot of abuse and the hot summers don't help. It's a lot tougher for an SpC stall to cool down in 100F heat than it is in 70F temps.
Anyway, it sounds like Tesla is aware they have some issues. He also said currently the entire west coast is serviced out of Fremont which means the techs end up spending a lot of time on the road. They are going to be basing the techs more regionally including this one in Vancouver, WA.