I've always tried to have the least rotating weight possible. It makes the car much more responsive to throttle inputs. It accelerates quicker, decelerates or "shuts down" quicker. It improves the effeciency of the drivetrain increasing runtime. I've just never found a situation where the drivetrain could be "too light!" Yes, it is different to drive. You need to be smoother with the throttle, both accelerating and decelerating. Personally, I think if the drivetrain is free enough (good bearings cleaned well, nothing bound) the car will roll just fine off power. It won't roll as fast, but you can always just let off the trigger slower or later......
I also race a full size stock car. We do everything we can to keep especially rotating and unsprung weight to a minimum.
I've just always felt that a lighter drivetrain can potentially give the best performance, after you adapt your driving to it.
there's my two cents