Not personally...we missed it last year due to illness (both the kid and I got sick on that trip...on different days! Really threw a wrench in plans)...
However, I know several people who have done it, ranging from the kids packages to the adult packages. They all have had nothing but glowing things to say about it.
If he's a NASCAR fan, he'll enjoy it. Even if he's not, he'll probably still enjoy it. And, if he would rather try a non-stockcar option, they have added luxury cars as well...
Haven't done it at WDW, but I have done an "exotic" driving experience before. It was 6 laps in a Lamborghini Gallardo, and it. was. awesome. I can't recommend it enough.