I have a 140mm travel 29er.It is the version with full Carbon front and back, Fox Factory CTD Kashima suspension and XT all around. Reverb stealth dropper.
Absolutely love it. It is light enough to do all day XC epics and the Fox CTD lockouts work well for this.
It is strong enough to do burlier things, it held its own in Wales many times, a long weekend in Molini and saw me do well in the ‘Ard Rock.
In my riding group there are people with Alloy versions, some with Rockshox instead of Fox, 29ers and 650b versions. All seem to love their bikes and none have had any real issues that I am aware of.
As much as I love mine, I have just bought something a bit more downhill orientated.It is now for sale in the classifieds – let me know if interested.
http://singletrackworld.com/forum/topic/fs-cube-stereo-hpc-29er-140mm-m