We were down in March and last May using T-Mobile and made these observations:
Poly - Main Cerem. House, no. In room (FIJI) , no. Outside on patio, good. Poolside and elsewhere - good. Basically walk outside.
Parks - Good signal outside
Port Orleans Riverside - rather spotty contact, worked outside main lobby, but not at Oak Manor.
Wilderness Lodge - Good ouside
Overall reception was better this March than last May..may have added a tower?
Artemus