Re: Polynesian vs Grand Floridian
I've stayed at both many times over the years, and in fact I've never stayed off the monorail at WDW. Given the ages of your kids, I would go for the Poly. It has a great pool and beach, good casual restaurants, and a theme that even young children can appreciate. The character breakfast at 'Ohana is popular with families, and transportation to MK is usually excellent. The rooms are spacious, and the amenities and service are excellent. The GF is definitely a more adult resort, so maybe give it a try after the kids are a bit older.
Walt Disney World has become a touchstone for me, a constant in a world where everything changes. Again and again I have come back to this place, grounding myself, communing with all the people I've been.