I also used a voucher here. I made a reservation ahead of time, got seated in about 5 minutes and the food took maybe 15-20 minutes to arrive at our table but the place was packed, so it's totally understandable. Yes it was not the greatest sushi of my life, but I still enjoyed it, all the food we ordered tasted fresh, and our waitress was pretty friendly, so how on earth can people complain for paying around $20 and getting $45 worth of fresh fish? You get what you pay for folks, if you are expecting a 4 star meal, you may wish to pay more than $20.
Would I eat here again with a voucher? Absolutely I would. Without one one? Maybe not but only because they run deals here literally 24/7, so why not save a few dollars and buy a voucher.
P.s. the sushi pizza was delish :)