The first thing I noticed upgrading from IC2 1.71 is that chainsaws now drop leaves (as per the release notes). The second thing I noticed is that the leaves are now useful because it provides extra recycling material. The third thing I noticed is that I no longer had saplings to replant my forest.
I think the chainsaw should have two modes, one for shear-like action, and one for sheer destruction. The only difference between the two being whether or not things like grass/leaves/etc drop. Perhaps on shear mode it would also make sheep drop more wool... when you "shear" them with your chainsaw