I know about the gearing, I met a guy with a modded Regal GS a few weeks back. He pulls on me quite hard, in a stock looking Buick! Haha, we must have ran like 5 times, that thing is quick. But once we go above ~160 the gearing on that car is hopeless.
What a sleeper though. I've always liked the idea of getting a GS over the GTP, and he just convinced me.