Let me tell you the basic difference between these three style of drivers.

The X/Speed is for the better golfer.  The better golfer meaning good enough to shape shots, to hit all different kinds of shots.  This driver has a very square/flat face.  To be able to shape shots on purpose, you can't have a driver that is made to help you get better results on off center hits.

The F/Speed is for the average, even above average, golfer.  This driver helps you get the maximum distance, even on off center hits.  This driver head is the typical driver face, but is slightly closed. 
The slightly closed head helps correct a slice, or allows a straight hitter produce a draw.

The M/Speed is the OFF SET driver.  This is for the person who hits a major slice, or simply is unable to get the club head closed during the impact point.  The OFF SET model assists the player in making the club face hit the ball in a closed position.

To make a long story short:

X/Speed - the scratch golfer who wants/needs to shape their shots

F/Speed - the average to above average golfer who wants the most they can get, even of off center hits

M/Speed - the beginner who hits a slice, or for those having problems getting the club head closed at impact.  The club face being open at impact is what causes the ball to slice.