It needs more room than the D606, with the popular 13/46 or 13/47 sprockets I'd run a 112L chain to prevent it from rubbing on the mud flap.
I liked it off-road, super traction in every and all conditions, from slick mud and rocks and roots to loose gravel, deep sand, etc. Not the best on pavement, and I had my second one fail by separating at the tread on the center knobs last summer. In the end i like the feel of good knobs better, but if I was using the WRR as a trail only bike the MT43 would be one of if not my top choice.