I've seen and handled the MKI in person, but not the MkII. There was one comment that summed up the MKI knife perfectly, I forget where I saw it:
"This is a YAK killing knife it's so huge!". It really is worth seeing one in person. Sorta like going to see the wonders of the world

. Seriously though, the differences are the MKII has about 1/3 less of an inch in blade IIRC, no seat belt cutter, and the carbide glass breaker is at the butt of the knife to aid with pressure point manipulation (it's at the other end on the MKI). I was considering buying the aformentioned MKI at a slightly higher price, but decided that college doesn't pay well enough (nothing at all) for me to purchase at that point. I probably would have sprung of a MKII, just because the man I knew who carried the MKI was 6'4", 270 pounds, and just a HUGE dude. He EDCed it seemingly with no problem

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On the other hand, the special edition MKI, with a non-marked blade, sharpened false edge, and marlin spike is apparently the standard issue knife for SEALs. So if you need to play DEVGRU in the backyard, I'd say you'd be better off with the MKI.

Seriously though, I could also argue the MKI makes a better choice for another reason: the seatbelt cutter. Instead of being "Tactical Death Machine 2009" in court, it's "Tactical Death Machine 2009- with possible safety features!", which may be more defensible in court (If I needed to escape from my car, I have a tool!). OTOH, if you're at the point of trying to defend any MOD knives as non-offensive weapons, you better start taking a liking to orange jumpsuits.