We just got back from PDC and we visited both Xcaret and Xel Ha. We throughly enjoyed both, I think it depends on what types of activities that you're interested in doing...
Xcaret: There's more of a variety of activities to do here: water (underground river etc.), animals (don't miss the sea turtles and butterfly pavilion), and the amazing cultural night show. It's a really packed and long day.
Xel Ha: Water activity based. We loved the snorkeling here, and the day went by way too fast! The day was much shorter than Xcaret, as the park closed at 6pm.
For both parks, I'd advise waking up early and getting there right when the parks open. We did this, and basically got to do everything, which was nice.
While we loved both places, my bf and I did enjoy Xel Ha a bit more. We had a wonderful time snorkeling and seeing all the fish. The best thing would be to try and squeeze a visit to both as they are so different!
