Has anyone on the board visited Chichen Itza as part of a trip to Belize?

We'll be in San Pedro later this year with another couple that wants to visit a "major" Mayan ruin. They specifically asked about going to Chichen Itza on the Yucatan on their return to the states. We've suggested that they might want to consider a day trip to Tikal instead.

Any suggestions regarding either location?