The M1 is available in both 460cc and 440cc clubhead sizes. It sets itself apart from other drivers because of its adjustability. With the TaylorMade's T-Track System, golfers can adjust the M1's center of gravity to adjust ball flight to their individual swing plane. Simply adjust the 12g weight forward for a lower flight trajectory and more distances, or adjust the weight back in order to correct hooks and slices. In addition, the M1 can adjust its loft +/- 2 degrees for more adjustability using the aluminum Loft Sleeve, which also allows golfers to adjust the angle of the clubface. The M1 also features 3 premier graphite shaft options standard with the option to customize you shaft.
TaylorMade's M2 features a 460cc clubhead and also features some, but not all, of the adjustability of the M1. The M2 does not have the T-Track System, but does have the same aluminum Loft Sleeve as the M1 allowing customizable loft and clubface angle. The M2 has a center of gravity that is much further back from the M1, allowing for an increased MOI (Moment of Inertia). This also allows for a larger, more forgiving sweet spot than the M1. The M2 also has fewer shaft options, with the Fujikura Pro XLR8 56 graphite shaft the only standard option offered. In addition to the standard M2, TaylorMade also offers the M2 D-Type which features an offset clubface to help eliminate sliced shots.
The largest differences between the M1 and M2 is how easy they are to hit and how adjustable they are. The M1 features a smaller sweet spot and is much less forgiving. It allows skilled mid to low handicappers to shape shots that less skilled golfers are unable to hit. The M2's design allows for mid to high handicappers to get more distance and minimize the risk of wild shots. The M2 is also less adjustable than the M1. For golfer's who enjoy the ability to dial in their clubs with adjustable weights, the T-Track System available on the M1 is the only way to go.
Which driver is right to you depends in large part on your abilities. The M1 driver will likely prove frustrating for golfers who are high handicappers. Likewise, for low handicappers or scratch golfers, the M2 will not provide the ability to shape shots that more seasoned golfers demand. Both clubs are solid choices, but getting the club more tailored to your abilities will result in more enjoyable rounds of golf.