I noticed a response above that brought up "loyalty." I wanted to point out that I have no ownership in MVC. I'm actually loyal to a different system, and for a reason that doesn't prioritize resort quality.
Once contracts are sold, the overwhelmingly main profit source of the operations arm of a timeshare or vacations club is management fees it receives for, well, managing the property. Developer gets contract sales revenue, of course, loan interest, some other financing related fees. But there is money made in the management itself, and this is not something the timeshare companies farm out. Not only would that mean giving up a huge revenue chunk, the company would also be delegating control over its brand perception.
If I had the money to burn, I would definitely want into DVC first, and then MVC. Not because DVC is better, but because we like being in Disney. Yes, DVC has quality resorts, but that wouldn't be my impetus for owning DVC. Alas, I don't have the money to burn, so all I can do is admire BOTH systems and their owners from afar.