Slightly terrifying, mostly fun.
My team booked this as a team off-site activity while we were in Vegas. I wasn't too sure about this since it was basically operating construction vehicles that I didn't have too much interest in, but I had a pleasantly great time.
The staff here are very knowledgable, and the sessions we had were pretty fun. The bulldozers honestly looked more fun than the excavators because you get to get quite vertical after you make a your own little mound to climb up on ... but excavation was pretty fun as well.
The whole thing is frankly a lot harder than it looks, and it gave me new appreciation for construction & machinery used for construction because as far as I can remember seeing, they always looked much smoother and easier to operate than they actually were when I've seen them "out in the wild."
Definitely something that's interesting to do on the side in Vegas, outside of the normal drinks, clubbing & buffets.