My family of 4 has stayed at both and we love both. But when it came time to plan our special celebration trip, and we considered where to stay, the answer was unanimously the Poly. There's something extra special about the location of the Poly. The view of the castle from the pool cannot be beat! And while the WL is beautifully and elaborately themed, when I'm in Florida, I really want palm trees and tropical flowers. That is a personal opinion, of course.
If you love the boat transportation at WL, don't forget that the Poly also has a boat to MK, and it has immediate access to the ferry at the TTC. I admit that I will miss the big open lobby with the fireplace at the WL, and DH especially will miss the hot tubs, but other than those 2 amenities, Poly offers everything that WL offers and MORE. We are really excited to be going back to the Poly!
Not to confuse you more, but you did ask for other deluxe suggestions...have you considered BC/YC? They have the biggest (many say best) theme pool on property, and you can walk from there to Epcot and DHS. Your kids are probably a great age to appreciate all that the Epcot resort area has to offer. We have never stayed there because we are not turned on by the theme of those resorts (we spend time at the Jersey shore, so we get our beach/yacht fixes there), but I think it might be worth thinking about for you. Price-wise, those resorts fall somewhere between WL and Poly.