I cut the edge on my Machax down by almost 50%, its now about 15 degrees per side, lightly convex. I have done a fair amount of chopping with it on soft to medium wood, and it has held up ok. Some chipping and denting, visible, but fairly minor (1 mm to 1/2 mm long and half as deep) . I have avoided knots though and made sure that I was chopping in clear wood. Will do some heavier work later on, possibly this weekend, but likely the next. I have some lighter stuff to do first and want to prevent excessive metal removal as the damage might be significant on seasoned bone and such with the thinner edge.
-Cliff