Bought a Groupon here, followed it up with a purchase of a Living Social coupon. Both were for similar multi-race offers. I would say, it's a great service and provides some fun entertainment right across the freeway from a central strip location. Staff was helpful, racing suits were provided (Though not really necessary) and best of all they had a helmet large enough to fit my head, and yet another one a size bigger. Who would fit into such a helmet the world may never know.
Not sure it would be worth the normal price, which is why I ding it a star, but with a coupon it was great! It might be worth it though if you are comparing to more expensive on the Strip activities though.
Also I would say it's more for adults than kids, when I saw a few kids going around the track they seemed more scared at the fast speeds these carts went and generally went very slow.