The
Grand Floridian Resort and Spa and the
Disney Beach Club both offer top-of-line experiences. I've stayed at them both several times and you really can't go wrong with either one. I'd say that the choice really depends on the ages and interests of your children.
If your kids are small and will want to spend the majority of their vacation at the Magic Kingdom, then that monorail access offered at the Floridian is unbeatably convenient. You can also use the monorail to get to several great character dining experiences at other resorts, notably
Chef Mickey's in the Contemporary and
Ohana at the Polynesian. These both offer lots of fun for the little ones.
If your children are a bit older and you will want to share the great international foods at Epcot with them, then the Beach Club is the way to go. I LOVE being able to have a great meal with my family at the
Rose and Crown at Epcot's World Showcase and then having just a quick ten minute walk back to our room at the Beach Club.
The other possible deciding factor would be your family's interest in swimming. The pool at the Floridian is great and has a nice water slide. But the pool at the Beach Club (actually a giant pool complex called Stormalong Bay) is truly outstanding. Stormalong Bay has a shallow sandy-bottom area for toddlers, a junior water slide for younger kids, as well as a drifting river area for adults and older children. Also there are a super-fun whirlpool zone and a really spectacular water slide or big kids.