I would rate Nobu somewhere between 3 & 4 stars.
Pros: Nice ambience, good service, fresh sushi.
Cons: Hard to get a table the same day, somewhat over-priced.
The server recommended the jalapeno yellowtail sashimi, which was great. The other sushi rolls we ordered were average. We also ordered toro, but when it came out, it didn't look or taste like toro. Strange...
All in all, I was staying at the Hard Rock and had really wanted to try the famous Nobu - While there was nothing WRONG with it, I just think that for the money there are better sushi places in Las Vegas.