If not the best Pho in the valley, I'd say it's definitely top 10. Unfortunately the place is a bit small, so there usually is a long wait specially during popular hours.
The food is excellent, the Seafood Pho (Pho Hai San) is probably their best Pho dish, although they also serve their specialty Pho which isn't too far behind.
The staff is super friendly, and always on top of things. Overall I give it a 4 out of 5 stars due to the obvious limited space issue.