I have a roam sim for my iphone. I have not used it at Disney, but I have used it in upper new york state. I had no real issues with it. The place I was staying at(a cottage) was just outside of t-mobile/roam coverage so my reception was hit or miss, but that is really a t-mobile issue. Once I got closer to a town it worked great. I like the fact that my number stays for a year, and that I could pick it up at a local store. I plan on using it January and will happily report back on my experience with it at WDW.