We went to Pho So 1 in Randolph on Sunday at noon to pick up some food for the Pats game, and the place was packed! Nearly every table was taken, and it was, with one of two exceptions, all Vietnamese families having lunch.
It looks like they picked a good place for a second Pho So 1 (the other being in Dorchester), as it has been crowded the last few times we've been there.
And the food is among the best Vietnamese I've had in the Boston area, if not the best. I'd say that only Saigon in Allston and Hu Tieu Nam Vang in Chinatown rival it, IMHO.