10" true vertical travel. More than enough when properly dialed in. Note: when dialed in, you should feel your M10 bottom out occasionally on the biggests whoops. This way you know your are using the full available 10" of travel. One thing I learned through proactice is that the M10 feels "soft" and collapses a little more when the rider boards the machine, but it "stands up" at speed so you get the full 10" of travel on the trail. I initially set it way too stiff (like a poor-action skid) to keep it from squatting when I got on the machine, but then loosed it up to let it work and really enjoyed it more then.
It does take some work to dial them in, but trust me, you WILL be glad you spent the time and effort as you enjoy the ride even when he trail are bumpy.