I have the EDMF version of the smatchete. It has a 10" blade and a hand guard. The blade is about 3/16" thick. It has sharpened edge about half way down the back, so it is not truly double edged like the other versions you mentioned. The blade is some version of carbon steel, L6 I think, but maybe something different. The edge hold up very well. I dont recall it ever chipping really, or dinging up really bad, even when I was throwing the thing. It splits wood pretty good, but its overall chopping ability is in question. I think the edges could have been ground with a higher bevel to improve the chopping ability. I caught my step brother using it to chop dirt once. It was very dull, but no damage. The balance it a little toward the handle, so maybe the 11" blade would chop better. I havent used it in a while, so I dont have any recent stories about it.
Also, I havent done any comparisons w/ any other version of the smatchete.