You asked which resort we liked best -- my answer is definitely Yacht Club. Our stay at the Polynesian was fine, but we find the YC to be much more luxurious and we like having close proximity to two parks instead of one. We also eat a lot of our meals in World Showcase, and it is much easier to get to EPCOT from YC than from the Poly. As everyone else has said, the pool also is a big plus. At YC, you have the shallow sandy pool and a small self-contained pool (with its own small slide) as well as the bigger pools and slide. We have never traveled to WDW with a child younger than almost 5, though, so the MK location might be worth doing poly. My 8-year-old would pick YC, though, if that helps -- he stayed there at age 6, 7 and 8.