The restaurant, MB, in the Grand Aqua, would definitely be your best bet. I have not been there, but I definitely know Michelle Bernstein's cuisine and she is fantastic. She established Azul as one of the best restaurants in Miami before leaving to Cancun. (She was the chef, not owner, of Azul).
I was in Cancun about 3 years ago and wanted to have authentic Mexican cuisine... no such thing in Cancun (at least back then). The concierge sent us to some ridiculous dinner show!
My opinion, go for MB, and PLEASE let me know how it is!

-Eli