Our family of 6 (all over 18 ranging from an 18 year old female of about 100 lbs to 46 year old dad of more than 100 lbs) did the ATV tour and were thoroughly impressed. We all had our own ATV and were all at least experienced as riders, although not at an expert level. You don't need to be an expert rider to do this tour. The guides were welcoming and friendly and depending on your experience level, were accommodating enough to allow a little wiggle room from the regular rules.
They advertise the average speed is 6-12 MPH, which is mostly accurate and while there are sections with higher speeds up to 25-30 MPH, it all depends on the skill level of your group. Riders with less experience will most likely stay in the 6-12 MPH range and be perfectly safe. The experience was still phenomenal and the views are breathtakingingly spectacular.
If you're looking for the ATV X Games, this isn't the tour for you. It isn't the bunny slopes but it also isn't the Olympics. If you're looking for an outstanding trail ride with medium difficulty and views that you won't get in many other places, this is the place for you. The trails are bumpy with steep climbs and descents in some spots, very dusty in others and well worth the time and money.
When I say very dusty, I mean just that. You will run into sections on the trail where you can't see 3 feet in front of you. It is temporary of course once the wind clears the dust, you are on your way again and they discuss all of this in the opening safety briefing prior to you leaving. You will be coated in red mountain dust when you're done. They have plenty of baby wipes at the end, just be aware that you will get much more dirty than you might expect. The required and provided helmets and goggles help a lot but the rest of you will get dirty, just be aware. 4 of the 6 in our group wore longer pants and the other 2 wore shorts and were fine. Some people may want to opt for long pants and long shirts but it is all up to each person and how dirty they want to get.
Some people will say that the drive in to the main launch spot is only accessible by Jeep, which is not true but a Jeep would probably be a solid choice. We did it in a minivan with no problems. They are a family run operation and the farm animals around the main launch area are wonderful. Peacocks, chickens and pigs aplenty. Cats everywhere, obviously horses and other animals make it a very welcoming experience. They accept cash and Venmo for tips. The ATVs are safe and very well maintained and fun to ride.
Highly recommended and we would definitely do the excursion again when in Maui.