We rented two RZR-S for myself (51), my wife (47) and two kids (Girl-19 and Boy-16). We did the four hour option and it worked perfectly. Any longer would have been too much for my wife. The RZR that my son and I had stalled after going through a puddle and would not run. We had to call the office and they brought out a 900 to replace it. It was about a 20 minute wait. The upgrade to the 900 was nice but we would have preferred to keep going without the interruption. On our way back to return the rentals, our 900 stalled on the main road. We blocked traffic until we could get it to a business driveway. It was very stressful and a pain in the butt. For the money that they charge, there is no excuse for this (although they blamed it on poor fuel venting). They also give you the option for tire insurance ($33 for the two) when you pick up your rental. Do you risk it? I hate these type of add-ons! Just include it in the rental price! Also, the maps that they give you are missing some of the route numbers that you see on the trail and the picture book was confusing since it says to skip things that shouldn't be skipped. They weren't very good IMO and we spent valuable time trying to figure out where we were going. All that said, we did have a great time when we were riding the trails.