Food is good. It's not quite up to par with the Columbia and Mount Vernon Akbars (I believe the Akbar owners once owned this restaurant as well), but I have eaten there many times, and I've never been displeased with any of the dishes I've had. Atmosphere is better than could be expected from outward appearances -- basically, your typical dark banquet hall setup. Location is off the beaten path. Getting there means running through the gauntlet of lights on Liberty Road, and that stretch of county has seen better days.
PROS: Food is good. Buffet is a great deal.
I usually go to Pho #1 down the road, but decided to give Pho Nam a chance on a day when the former closed early. I'm glad I did. The restaurant itself may be an unassuming hole-in-the-wall, and the menu has maybe 20 items on it, but the food is great and the service is lightning-fast. To the reviewer who complained about no vegetarian dishes, perhaps you should have done some research before going there. Pho is non-vegetarian almost by definition, and you're not likely to have any luck at an authentic pho house.
PROS: cheap, good, fast
CONS: lacking in ambience (definitely not a "date restaurant")