Here is what I would rate the different food items, based on what I've had in the past:
Herring appetizer - 3.5 out of 5
Borscht - 3 out of 5
Russian salad - 2 out of 5
Schnitzel and potatoes - 3.5 out of 5
Kvass - 1.5 out of 5
Napoleon - 2.5 out of 5
Overall, it's not a bad place, but I would not say it's a must go destination.