I have to admit that I was more excited about swimming than visiting Mayan ruins (shameful), but we did visit them nonetheless. We went at around 8 in the morning (yes, we were vacation ambitious) and I liked that all of the visitors seemed to be Mexicans and not tourists. Chris and I were oddballs.
The placards explaining the ruins and their historical context were hilarious because they were translated pretty literally. For example, "...The boats couldn't resist the turbulence on the open sea..." I think the boats must have fallen hopelessly in love.