Assuming Tesla puts Superchargers in the San Francisco->Seattle run, I imagine at least to start they would only be on I-5 starting well South of Seattle. But there's a lot of us Roadster drivers in Seattle that are used to going North and East too, using other HPCs put in by owners. At 70A, they are much faster than any of the other L2 charging options. So it would indeed be helpful if S owners could use them. (Although up in WA/OR, I'd be happy to trade an HPC adapter for a CHAdeMO adapter! They will be faster and much more numerous than HPCs. They will be common in CA's metro areas too; CA is still trying to get them on I-5, but no luck with funding yet).