We have only been with MSC in YC (Fantasia (1), Divina (1), Preziosa (5), Seaview (1) and Virtuosa (1)), so not able to compare. But food is generally good and well presented. Not exactly fine dining Michelin star though is my view, but close.
Amongst the things you might enjoy include: attentive service, unlimited drinks (but each drink to a max value, not sure if $14 or $16), unlimited access to the spa, priority boarding/tenders, exclusive lounge, restaurant, pool etc.