Damn, ouch. Seems crazy that they're now in the position of breaking supercharger compatibility with existing cars.

No compatibility break as far as I know. I believe V3 superchargers speak CCS to 2019 and newer cars and fallback to the older Tesla-proprietary communication if necessary.

Sure, but some Tesla owners are going to be surprised when they pull up to a third party charger with a Tesla plug that doesn't work on their car even though it plugs in.

Only ~once.

A little bit of pain when there aren't that many vehicles is fine if it makes things quite a lot better going forward.

I just scheduled the upgrade for my 2018 Model 3. It’s not free, but only costs $280 and they do it in my driveway. Rumor has it I might get a CCS adapter out of the deal too, but I’m not sure. It’s an older car but still going strong, and my biggest concern is that if I don’t do the upgrade now they’ll run out of upgrade kits and the car’s value will be permanently damaged even if it lasts another ten years.

Yes, you get a CCS adapter bundled for no extra charge with the retrofit. I just had mine done.

So retrofit + CCS->NACS adapter for $280 from Tesla cf. NACS->CCS adapter for $225 from GM.

ah, gotcha. Yeah, I can live with broken compatibility with just the newer non-Tesla chargers, especially if the upgrade is as cheap as folks here are saying.