My R1 driver isn't 3 years old yet, and it's already 3 or 4 generations back!There is a slight problem with this thread in that though the gains from the R15 to M1 might be marginal my understanding is that in general you might want to consider changing your driver every 3 years. So should we really be talking about whether it's an improvement on the R11-S or other brands driver releases from 2012...?