We had a fine time, but it wasn't as thrilling as I thought an ATV adventure tour would be. It was described in the safety briefing as an eco-tour - no slingshotting, stay within 3 lengths of the vehicle next to you single file, and no drifting. This was more like a bumpy mountain road ride, which was fine. We were also stuck at the back of the pack, so the dust really kicked up back there.
And the dust! That was no joke. Red volcanic dust will get stuck onto you everywhere. Beware of any white towels you have back at the rental - they will get stained even after multiple rounds of scrubbing and soap.
The views were amazing though, and it was cool to see Maui from a different perspective.