I have been very happy with Sonic in SF and figure that I should give them a shot. I learned that in RC they're just reselling the AT&T service, but they reassured me that I should expect much better service. Regarding the install, I was assured that while AT&T would do it, because of their relationship with them I should not expect any issues and, if there were any, I could quickly escalate through them.
As it happened, during the window I got a text saying that the AT&T installer should be there. I called them to confirm that nobody was there and they told me that I should just ignore the text (?!) and somebody should be there eventually.
Nobody ended up showing up. And when I called to escalate, the solution that they came up with was to give them a few times that might work better and that they would get back to me the next day on whether any of those worked, because the department that handles that was closed after 5pm.
At that point, it was clear to me that this service was just AT&T, but more expensive and with extra steps and figured out that I might as well go back to dealing with AT&T directly. To their credit, the Sonic folks did not give me a card time and started processing the cancellation right away. Unfortunately, it's not instantaneous and until it goes through on their end and AT&T's, AT&T will not engage with me as their position is that there is already service on that address.
As I said earlier, I am very happy with Sonic in SF and if "real" Sonic was available in SF I'd take it in a heartbeat. However, I am having a hard time understand how resold AT&T makes any sense given that it's more expensive, you're tied into a contract, and if there are issues, Sonic being in the middle just makes everything more painful than dealing with AT&T directly.