The Charters are different than a DVC MC.
On the Charter, you are getting the regular
DCL experience, but you are traveling with all DVC members and their guests. You may get an exclusive gift. Last year they gave out the book “Making a Disney Wish.”
The DVC MC include regular DCL activities like tastings, trivia and the theater shows, but will also have exclusive activities. There has almost always been special Broadway singers for instance who put on an amazing performance. There could be Imagineers, Disney Legends, Movies shown before the official opening, and unique gifts given out every night.
I will be on the DVC MC this September and am very much looking forward to the Member Cruise experiences.