I booked via Viator.
Experience: over 6 miles of driving on private dirt roads - not a vendor in sight, no kids running next to you trying to sell you anything unlike the other dune buggy excursions around. After being picked up in an open truck, got to the ranch, went through safety tips and rules, got our helmets, and a quick demo of how to drive automatic buggies. It was only 3 groups of us 3 buggies, but they had 1 leading buggy and 1 buggy trailing mechanic - although none of our buggies faced any issues. We drove FAST. Super bumpy and it rained a little the night before so there were some mud holes.
Our first stop was at a dominican house - we got to sample coffee, see the garden, home, chickens. Not a vendor spot - just a local home.
Second stop was at a natural cave - a little bit of hiking inside, but very cool to see. The cave leads to Bedrock City - the Flinestone's portion of the tour - a trip down memory lane for replica Flinestone's home and something for the kids.
Then we drove all the way back to the ranch. If you are looking for a private, safe, fun, adreneline pumping dune buggy experience, this is it. Highly recommend it. Our tour guide Ivan was awesome and funny.
Only downside was the pickup time was that its not stated clearly stated in your booking confirmation. Only advice is to make sure you have a clear understanding of what time you will be picked up from the hotel. I tried calling while in DR, but i think the quickest and best response was via email. Email them after you book for your pickup time.
But still a great experience and highy recommend it.