I always think horse riding is worth the money. Most of the time for me, though, it's free ... if I want to go to the effort of saddling up the horse. Which I don't always.
I've done 4 different riding excursions in the Carribean, but none in Freeport so I can't tell you about that one specifically. If you haven't ridden trail horses much, they're extremely broke. Which is good for novices.
Most horses in the Caribbean are also Paso Fino. This is a smaller breed, very wiry and thin, lots of stamina and considerably smaller than a typical American Saddlebred or Quarterhorse. As a result many people come back thinking that the horses are starving to death and they're being abused and mistreated. Baloney. They're just smaller.
If this is an opportunity to ride on the beach, keep in mind that the commercials showing same are "professional drivers on a closed course". You won't be galloping through surf. You'll be wading, possibly as much as fetlock deep, in a shallow lagoon with no waves until the guide tells you to come back to the dry sand -- maybe as many as two minutes.
Enjoy.
Desperately seeking 10th cruise for the free laundry.