We had a fantastic time at Xcaret, even with a few of the attractions (river tour and monkey island) being closed. If you aren't doing any of the additional activities then a day is plenty of time but just do a little of planning when you're there, I found the app really helpful because of the map. The show is absolutely worth the hype, it was incredible. We did the dinner with the show, the food was just okay but the staff were very helpful and you get really good seats. Wear comfy shoes (and water shoes) as we did 22k steps! Overall we had an amazing time at Xcaret.