It's a big competitor of Hong Kong Market Place in Arlington area. They offer similar prices and similar variety of goods but there are always some goods that you can find in one store but not the other. I think "Saigon" is a bit cleaner than "Hong Kong" but generally the price is bit higher and there are more mis-priced items (the price on tag and actual price are different :<). Though the on-sale items are quite attractive.
Suggested item: Beef franks for roast