"There are two locations: the original is on Reseda, just north of Sherman Way (with parking in the back), and the other is on Sepulveda, just a couple doors down from the 99 Ranch Market, on the corner. Both locations are great, although some believe the Sepulveda spot is a bit nicer since it’s newer. It is also smaller, but both can get quite busy during lunch and dinner hours.
Pho So 1 offers a good selection of Bun dishes, which is not the case at Pho 999. Their egg rolls are larger, and the variety of herbs they use is usually greater. There's also a wider range of rice dishes available. Overall, Pho So 1 features a more extensive menu, and I believe the food is significantly better prepared. I have friends in Altadena who have tried local Vietnamese restaurants, but they prefer Pho So 1 so much that they are willing to drive all the way to Van Nuys just to eat there. Another friend from Santa Barbara insists we visit Pho So 1 whenever he’s in town. I encourage you to give it a try and see for yourself, but I’d wager you’ll agree that Pho So 1 is the superior choice."