They shouldn't advertise it if it's not very good at times. My GF's husband has to have internet & access to his emails for work while he's away. He bought a data plan for while they were away & said they would have been in trouble if he didn't buy it & only relied on Disney's.
I had to go into the common areas to use my wifi & still wasn't great. It was ok if you were near the main building though. We were in building 7 & only late at night would I have a signal & it wasn't very good. I would find if I was in a hotspot all of a sudden my phone would start going off because it would finally connect. I'm not complaining since I didn't need it except to communicate with my friend who was there at the same time, but it wasn't very good IMO. I was using a BB.
My GF tried to change reservations for her dinner one night with her BB & it took her an hour, finally she ended up just using the phone & calling in the change.