We had a fantastic tour guide at Chichen Itza who was very friendly and informative. The food was great, but did not include the price of drinks, even water. This was not a big deal at all but would have been nice to have been prepared for.
The Dolphin Xtreme: Swimming with the dolphins and manatees was fantastic. Each person in our group got plenty of one-on-one time with the dolphins. There are no stingrays or sharks in the area, so that was disappointing... The rappelling, zip lining and snorkeling was a ton of fun! I only wish we had more time to these things - it felt a bit rushed. That guide was great, too, and the food was very good. You cannot have cameras with the dolphins and manatees, but you can with everything else. The photographers were great, though, so you don't NEED a camera.