Just to add an anecdote. I installed a new Shimano Exo-style crank last night. Used my handy torque wrench very carefully on the M6 clamp bolts on the left crankarm. Even being exceedingly cautious, the bolts still rounded out well below the spec'd torque. Had I not been using a torque wrench, I would have stopped much sooner, but that would have been bad too. Having the torque wrench taught me just how crappy those particular bolts were. Talking to the local shop mechanic this morning, he told me, "Yeah, those round out all the time. Never tighten them without a torque wrench unless you have to."