I ran mt21s on my KLR, they dont look like they'd work good on the road but you can realy push them without issue, offroad they're pretty good if you stay out of the mud.
A mt21 on the front and a d606 on the rear is a common set up on other dual sport bikes.
The mt21 front works better everywheres and last about the same.
The rear mt21 doesnt last as long as the d606 and works about the same, so the dunlop is prefered on the rear.