Guess I must be a dinosaur, because I’m just not keen on running a spool. My car always feels better with a diff. By better I mean smoother, more consistent, and more predictable. When spool equipped, the thing always has at least 2 or 3 abrupt and unexpected episodes during each 8 minute run that it just doesn’t ever do when fitted with a diff. Most notably, if I happen to cut a corner just slightly too close and I barely touch a dot even with just one wheel, the car will hook abruptly and nose into the board.