I've ordered for pick up on their discount menu multiple times now and this is by far the best value sushi restaurant I've eaten at. The quality of food is quite high. It sits comfortably above typcial sushi buffets and slightly below the authentic japanese sushi restaurants (although those are hard to find in this area). The variety is also fantastic. What gives this restaurant a high value rating is the fact that the prices are also quite low relative to what they are serving.
I haven't ordered the all you can eat so cannot confirm if they serve a different grade of fish for that meal option like some restaurants do. A simple comparison method between salmon sashimi that I usually do is to compare their salmon sashimi.
A la carte salmon sashimi will be firm, dry, room temperature, and 'crisp' to the bite, while buffet style is usally wet, cold, and a bit mushier to bite into.