I just put the Knarly on mine, I like the way it broadens the midrange, I'm shifting less now.
In the Dez the 13/50 pulls the sand great and also works well on tight ST but if it's open terrain or connecting trails I'm reachin for another gear allot of the time, doesn't help that I tend to ride it below the PB allot. Things seem to get a little crazy when ya start hitting the pipe hard
I've been running a 13/49, it's a little gappy in the sand but it pulls the long stretches without buzzin too bad. At $750 the 6sp might be nice, gives ya a little of both worlds.