We went here for a dinner at around 6.15pm. If coming at that time you can maybe get away without a reservation. If you plan to come after 7pm it's worth reserving as many people were being turned away.
When we ordered our food came pretty quickly and was good in general (though shrimp gyozas didn't taste of much- wouldn't bother with those if going back). We liked it so much we ordered more but this took quite a bit longer to come because the place was so full.
Service very friendly.