We did it on our 8/3 Western. Husband (37), myself (36), sister (28) and son (13). It was fun and I would probably do it again.
It was my son's first ride and he LOVED it. Husband is a natural.
It's a different type of riding (probably closer to Western and definately not English) because of the way the Mexicans train their horses. They explained all of this to us on the bus ride and did a demonstration once we got there. The reins are ropes not leather and the horses are a bit ragidy.
The "Ruins" are replicas of actual ruins, so if you're going to see ruins go to Tulum (my mother loved it). They take posed pictures of you on your horse which you can of course purchase, and there was free "pony"-sized cold beer and soda (all you can drink) afterwards.
The day was a bit rainy, off and on, which was a relief in the steamy bush. One this is to wear long pants (A MUST) and also shoes that can get dirty. This ranch is not aestetically pleasing, and you are walking in the dirty (or muddy puddles in our case) and I had to wash my sneakers

You do get to gallop and trot, and they pick the horses based on your previous riding experience (my son got a slow horse which he wasn't too pleased with because he wanted to gallop and go fast, but I was happy with it as it was his first time)
The bus is nice and is air-conditioned, too.
All in all, it was fun and for the cost was nice to ride again.
I hope this is helpful. Let me know if you have any specific questions that I can answer.
Michele