This past weekend we stayed at El Dorado Royale in the Riviera Maya, Mexico. Below are pictures showing the current Internet (wifi) prices and sign up details for the resort:
The speed was actually good. At first I thought it was worse than a cruise ships in terms of reliability and speed but it turned out that that morning a quarter of the resort was out. Once it was resolved we had no issues as all; in fact we were even able to FaceTime with our son that was home with grandma.
This was information I was interested in before the trip, so I hope it helps you as well.