We were just there. We rented a car from Crystal, they let you take the car out of Belize. The border crossing was and experiance, a young boy offered to help us get past, he earned his tip! It is a bumpy drive, but you see Guatamala. We stayed one night in Tikal, the idea was sunset photos, and sunrise photos. Well the idea was good, we had and afternoon rain storm, we did not care that we got wet, but the walking paths turn into creeks and are VERY slippery when wet. We are active and love to hike, I fell once, did not get hurt but it did make me alot more careful. Rain caused fog in the morning, so we missed the sunrise photos too. We did get many ruin photos,spider monkeys, howler monkeys, and tucans as well.
When we returned to Belize, we felt like we were home. We would do it all over again!
But I would not recommend the trip to those with mobility issues.