I decided to dig this thread up because I have both the xm-1 and its thinner-handled sibling the xm-2. Have had both for almost 3 years.
The Ontario Extreme Military series should not be compared to regular EDC folding knives like the Spyderco Military or, for that matter, most your regular folding knives.
The XM folder is a thick bladed knife with a strong grind. At 5mm, it's thicker than the Ontario RAT-3or the ESEE/RC-3, while its open dimension is roughly the same as all those fixed blades. What the XM is, is a compact military folding field knife that can take the place of a fixed blade.
This is a folder that can chop and hack, pry and dig. And the steel choice is perfect for a knife that has to undertake such tough chores. Yes, with such heavy use, the knife can develop bladeplay, which is easily remedied by a quick turn of the torx.
It's a good knife to pack when you need a very strong blade in a folding package. And at its price, there's no other knife as robust.