The PRO RMK chassis is the first that could actually utilize the advantages of the narrower stance because of the narrower body..
I had a set of 38's on a Dragon and found that it "paneled out" too much on counter-steer and sidehill moves... On the PRO... NOT at all!!
Timbersled offers a 38" wide set that is wicked on a boondocking PRO RMK.
The sled goes where you want with less effort with a narrow stance but does give up a little stability in certain situations.
It is less stable than a wider set... heck an Assault is more stable than a RMK...
Huckers and hill climbers will not want to go narrower... but boondockers and general riders, IMO, will.
With a 38" front end... The PRO Chassis RMKs maneuver in the tight stuff like no other and still give a VERY useable ride on trail.