Grassroots Motorsports had one of these on hand (along w/ a base Boss) during the $2011 Challenge.The Pro drivers in attendance for the Challenge were allowed to use the Luguna Seca, for reconnaissance laps on the course, to familiarize ourselves w/ it. The LS Boss was a pretty good right out of the box. The engine revved very smoothly all the way to redline--I was quite impressed--excellent powerplant.
The handling was actually very good. That being said, the car (even w/ the Pirelli Corsa tires) was no match for my GT-R on streeties, as far as overall feel/handling etc. The car was much more prone to break away @ the limit, and felt slightly piggish to me (even though they weigh abt the same now, after my car prep).
Advantage: GT-R--imagine that lol.
Thought I'd share...