I have a single gentleman sailing on the 11-night sailing on December 10th - got a great single rate!
He's cruised many times on all the major cruise lines and I respect his opinion, so it'll be interesting to see what he has to say.
MSC mainly caters to Europeans, who find them very nice. Americans, on the other hand, are divided. It'll be very interesting to see what changes they make to accommodate the U.S. cruisers and how they'll modify their brand.
I'd love to give them a try so I can find out first-hand how they compare to the other cruises we've taken. Hopefully, we'll get the chance before too long.