Ive been swapping for a few years between a 29er front end and 27.5 on my Trance and the last yr on the Levo. I love it until a front wheel washout, then I blame the bike setup, not the rider
Ive been keen on a Foes Mixer for yonks and really like the concept.
Downhill feels great , confidence inspiring to plow through the chunder, and climbing rollover helps me a lot. When your really feeling it, cornering is a blast, rear end feels like it whips around the corners, though on a meh day I sometimes doubt my choice, mucking about with geometry, higher front end etc.
I dont really think about it anymore as I auto adjust body position, but with tight climbing there is a little tendency to wander though its not s show stopper.
All in all I really like the mixed wheels. I tend to swap back to original wheel sizes every few months just to see the difference and enjoy both, 2.8 Butcher grids front and rear on Levo or 29 2.5 DHF and Butcher 2.8 front on Trance.
Give it a go and have a play, so easy to setup on the Levo, with the Trance its bit of a pain, od2 headset to be knocked out and swapped etc.
Oh, and on the pedal bashing Levo, raising bottom bracket is a bonus, though now im running 165mm cranks both bikes and all is good.
damn, another edit, also flat pedal users gotta try the Catalyst Pedals, never ever going back to smaller pedals, different foot position helps uphill , larger platform for downhill , solid.