I agree with some of the other posts, the place used to be better. I have eaten here several times over the past 5 years and it has steadily gotten less enjoyable. The service is slow. It took us over 15 minutes to be seated, even though we arrived on-time for our reservations (and there were no other guests in line). The salads and sushi took forever, as did our main courses.
My salmon was over-cooked, in fact it seemed like it sat waiting for other dishes. The scallops were very good, and most of the other people in our group thought the food was okay. The prices were fair for Las Vegas, and Mandalay Bay is a really nice property.
Our wait staff was slow on refilling drinks, I think they might have been over worked. We just didn't see them enough considering the wait we had for food.
The bottom line is that there are more unique experiences in Las Vegas to try. It can be loud, and the service is below average. There are many dishes that are great, but many are just average.