Long time KM rider here, and I'd like to give something new a try.

One of my KMs are set up geared and rigid. With a fat tire out back I can't run the wheel all the way forward as I run into FD clearance issues as well as chainstay clearance issues. This is made worse when cornering hard as even though I've got a solid rear wheel (Flow on a CK hub). The handling characteristics I get with the effective short chainstay is something I really like. Also, I personally find 9sp drivetrains (what I'm using) not perfectly suited for 29 rear wheels. The bike is used mostly as a "mule" bike - backwoods ventures on techy, rugged, steep hiking trails - sort of hiking by bike; and for access for "far out" trail work. On paper a 650b out back might make a better set up. A slightly smaller, tougher, wheel that could get up to speed a bit more easily would be nice. The expected geo changes would be small and actually something I'd favor.