The general concensus is the 756 rear loses its edge pretty quickly compared to the likes of an Metzeler MC4 or Michelin M12. It sticks good when it sticks good but then goes away. Other riders I know feel that it slides laterally more than other S-to-int tires in soft terrain conditions.
Pirelli MT44 fronts, MT32 F/R, and MT320 F/R seem to hold up pretty well too in the soft-to-int catagory.
We try to avoid the use of the term "best" around here if possible BTW. Too many variables.
Hey, if you're a dunlop guy then you're a dunlop guy so run the 756. If not stuck on dunlop, a dozen different tires will work for you as well.
Hope this helps,