I've been coming here for while a while, at least a few years. Finally I feel qualified to give a review.
Sushi Kuu is a fairly standard high end Japanese restaurant, of which there are MANY in Hong Kong. It is essentially Hong Kong people's favorite type of cuisine, so it's a really competitive space. The ambiance is quite nice here, so I would recommend it as a place to come after work with colleagues or with an SO or even your family.
I've had a lot of things here and most things are pretty good, though fairly pricey, such as the sukiyaki, the sashimi, the sushi, the cod... the cod is probably my favorite. Keep in mind though that things are pretty expensive here, so you might not necessarily leave feeling full.
Recently, Sushi Kuu has seen the effects of shrinkflation. For those of you not familiar, this is kind of like inflation, however instead of increasing prices, they keep prices steady but shrink portion size. Personally, I would prefer inflation, but I kind of understand why they do this.