I think it is nice to have a multi-generational vacation! I wish my parents would do that with us! I have written a lot to a potential cruiser about Disney vs. Carnival and Disney vs. RCL - so I won't repeat it here. It was not up to our expectations for our family. Food, service were very poor. If you decide to go anyway, will Grandpa go to the Spa and the adult pool (it was very quiet there just like DCL promises - the only promise they lived up to actually!). We never got to be there for more than 15 minutes as they counselors did a poor job with our daughter and they kept paging us to come get her. Had I been able to sit there and relax and it was a nice adult spot with 2 nice jacuzzis.
The BINGO onboard was also really fun. I am not a bingo person, but this one of the few activities that was run well and with humor. The social staff kept it lively. Everyone showed up (I turned 40 on this cruise -but saw all ages).
There is small learning component and lecture series - they had the coach from the Mighty Ducks onboard. There is an ESPN sports bar. The promenade deck was relaxing for a walk, run or reading a book.
JUST REMEMBER it is a hectic ship with a young child and the food in the main dining rooms is poor - really poor.
If you decide to do Disney there is plenty for everyone to do. There are several adults only areas of the ship that include Palo's (reservations have to be made for this, do it first thing after boarding if you can), Beat Street on the Magic (they have something similar on the Wonder), a lounge, a bar, pool, spa, etc. Plus not to mention the ports of call and the fun times to be had there!!!
I'm not sure why some folks consider it necessary to post a negative reply to every single post on this board, but I do think their experience is in the minority. We just sailed on Celebrity, which is an "adult" cruise line. We had a much better time on DCL. For one thing, our daughter was entertained, so we could enjoy ourselves. We were able to stay out at the clubs, enjoy the adults only restaurant, etc., without being worried about whether she was safe or having a good time. On Celebrity, they have rules about kids being in certain areas (the spa, the hot tub), but they aren't enforced. Kids were allowed in the disco until 11 pm on Celebrity, and they took over the dance floor. Disney does a much better job of keeping the kids out of adult areas. And by the way, my DD had Caesar salad every night on our DCL cruise. Diana
My inlaws also went on the Disney magic last year, both in their 50's and had a blast. They really enjoyed themselves and scheduled another. They recently went on a cruise to Alaska with Holland America and Mexico with Carnival.
my mother-n-law keeps telling me "Disney is just Magical" regardless if you bring kids or not. I hope he goes I'm sure he'll love it.