The service was exceptional. They also had powerful air conditioning on a rare, hot SF day.
There was only one 32GB, white iPhone 3gs in stock, and my sales rep, Monica, literally sprinted to the back to ensure that I got it, and not one of the other customers in the store.
Monica was also able to get my Verizon number ported over to ATT in minutes.
Who knows how the network will be - from understand, it is buckling under the weight of too many iPhone bandwidth hogs. But I have no complaints about AT&T's service or facility in the Mission.