Hand Tools Archive
Hardness isn't the issue in this case - the iron is about the same as a stock stanley (a good stanley, not a modern one) in hardness.
To me, it seems like the V11/XHP is a little bit less tolerant of defects or contaminants than plain carbon steel. Without a like comparison, seems like doesn't cut it, though.
I found the extremely hard plain blue steel japanese iron to hold up best on the mineral defect, which wasn't expected.