I use Sprint and had a great signal in all the parks when my family vacationed two weeks ago. We got full signals at the Polynesian too, but very weak signals last year when we stayed at Coronado Springs, so I guess it depends on where you are. Just a quick tip: my phone slipped into roaming mode a couple of times in my purse during the day, and it really drained my battery, so you may want to turn off the roaming option. I didn't even know you could do that; my ex-boyfriend who works at MGM had to show me! Good luck!