I've never had one of the M2 hardtails, but my M2 roadbike is completely unyielding. It's quite uncomfortable on extended descents on patchy tar, on the flipside it is a real traffic light racer and a killer crit bike because every bit of input to the cranks turns into forward motion. I've ridden plenty of bikes from back then to now and it's easily the stiffest, no flex up, down or side to side.
