General, I like the book a lot. It's a great way to bet NASCAR, in my opinion, and you get better lines on most drivers with the paramutual setup than you'll find at most books, and at all the cookie cutters. I would think that all bettors that want to play around with NASCAR would use them, as you can drop some small amounts, cover a few drivers and grab some nice payouts.
For the more experienced bettor, the quinellas and other opportunities give you a big chance at major payoffs. In short, it's an auto racing site that offers horse racing style betting. I would think it would appeal to anyone. They are also lightning fast with payouts. The management is serious about the market, and from what I have experienced and seen, they do a great job.