My chowhound girlfriend have eaten at most of NYC's nouvelle Japanese/tapas places (En, Megu, Maturi, Aburiya Kinnosuke, Japonais) and Butai is far away the best. Here is why:
1--The food. My girlfriend raves non-stop about the pork belly skewers (which she orders 3 or more at a pop). I am enamoured of the agedashi tofu (a tough dish to make stand out but they do) and the shrimp enoki...fresh, crispy and flavorful.
2-Ambience. Cosy, comfortable, and chic, without being pretentious (like Japponais and most of the others).
3-Service. Friendly and attentive but not solicitous.
4-Price. Really good value.
We have recommended this place to several of our friends (all discriminating about Japanese food) and they have all loved it and gone back.