Personally we love CG, but that being said, if I had a bunch of picky eaters & you were debating leaving the MK, I would just stay put. Although delicious, the food isn't anything out of the ordinary & they are accommodating, but the choices are somewhat limited & also somewhat expensive. IMHO I think it is a bit of a pain to leave the park, travel to the Contemporary & then travel back to MK, but doable if that's what you really want to do.
We usually plan a night at CG & watch Wishes from there & then we plan another night at MK where we can see Wishes right by the castle, where it is meant to be seen. I prefer to stay put if we go to a park & not travel back & forth.
The Crystal Palace is a buffet & the food isn't fantastic, but being a buffet means that picky people can choose just what they like to eat. The Winnie the Pooh characters come around & if you have little ones, that's always fun.
