I think it's a function of the edge angle you're forced into with a 3-blade head. It's just too steep to really put a hair popping razor edge on them. I've never used Snuffers because I can't get that really scary edge I get with my 2-blade heads.
I've recently gone to Magnus' website and checked out their sharpening instructions for Snuffers. They say touse only a 10" medium mill bastard file, form a burred edge and leave the burr alone. I've always tried to remove the burr and put that razor edge on 'em, and was never satisifed with the results. Obviously, that's where I went wrong.[&:]
Since the Woodsman is basically a stretched out version of the Snuffer, I'd say the same sharpening method should work for them too. Maybe I'll get a chance to try out that sort of edge on a few Snuffers before the woods get too much older.