I have to agree with Nancy. I suspect it all depends on where you stand on fine dining. The specialty resturants seem to be more focused on the server's presentation, than on a fine dining experience. If you happen to have excellent servers and are prepared to be treated (entertained) to a wonderful presentation for dinner, then you may be in for a great evening.
But, if you want to enjoy a wonderful meal and the companionship of your dinner mates, rather than the presentation of the dinner, then it may fall short.
Personally, I believe that an enjoyable dining experience has to do with the dinner conversation, personal interaction and overall opening of new relationships that are enhanced by the servers and meal. Such is not the case with some of the servers in the alternative restaurants on the Millennium class ships.
However, that is just my opinion and is probably jaded after too many cruises...VBG.
Give it a try and let us know what you think.