I own a Mach-I, LaGriffe, and Police Utility Knife (PUK_E).
Mach-I is a bit of a step child to Commander.
I happen to like the blade design of the Mach-I somewhat better than Commander. It would appear that I am in the minority there. A cross between the two would be better ... I like some recurve. I would prefer the Mach-I had a Wave also.
Mach-I handle design is very secure. I like the thick tip grind, stout... except for the last 1/4" where the meat-head at Emerson who ground it twisted it too far on the belt grinder and it's about 50+ degrees for that last 1/4". I only use if for self defense carry ... e.g. when I know I'm headed into the city. It isn't my favorite utility knife, to state it nicely.
After some fiddling w/ ball detent spring pressure, my blade is centered. Lockup is good enough to keep and use, and trust, but would prefer a stiffer leaf/liner spring.
I like it for a self defense folder.
It has a couple of fabrication problems, and I'd tweak the design in probably 3 or 4 ways, but most people in this particular forum don't get much use from such commentary, so I'll refrain.