All I am saying is that all of them cut better when they got past some "threshold" of chisel prep... It was very noticable - both on the stones and on wood...
As to the cause of it... I am not convinced it is specifically decarb... For several reasons... Patrick makes good points in the other thread about alloys used to reduce decarb problems... I noticed the same thing as he mentioned in my backyard chisel experiments... There was no noticable decarb layer to deal that persisted beyond simple adequate flattening and sharpening... I had no decarb problems even with a Mapp gas torch..
And I am not convinced it is from "Flattening" the back.... I think flattening the back has a side effect on whatever was hurting edge durability.. But I doubt "Flat" is the cause of better performance....
What I did notice last night is that when I re-honed the bevel on my Worksharp - the problem came back when chopping mahogany and eucalyptus - though not when paring mahogany, spruce, or eucalyptus end grain.....
Although it's nowhere near the extent of previous - it still feels like I went backwards somewhere.. It could just be my expectations, though.....
Do you guys prep separate chisels for chopping? If so - how? Is it possible that a finely honed and polished edge performs worse chopping than a fairly coarse edge?