Light tyres suck a dirty scone. Meat will give you confidence, allow you to push hard in a corner, grab in a sketchy climb. Your Nev's are a great all'rounder IMO. I like the Excavator more though the added weight and rolling resistance from the more squarish face where it contacts the ground may be a turn off to some. I still think the Nev or the Exc way overshadows the ultra light weight of a SB8 or Conti MtnKing.