I've owned a few Microtechs (DOC, SOCOM Delta, Ultratech, etc.) and eventually sold all of them.
The SOCOM Delta was definitely my favorite. Nice slim carry and a super smooth pivot. The downside was that the detent was very weak out of the box, so the knife could swing open too easily. Never really had an issue with it but the weak pivot was a real downer on an otherwise great knife. I tried to send it in to Microtech for repair. Dealing with their warranty department was a chore. Not to mention the fact that the turn around time is reportedly an extremely long wait. I opted to sell the knife.
The proprietary hardware isn't a huge issue in my opinion but as far as I know Microtech themselves don't offer any tools to breakdown their knives. All the ones I've seen are custom made tools and Microtech doesn't condone breaking down their knives anyway. Tat wouldn't be such an issue if Microtech's warranty service wasn't sub-par.
Then you have Tony Marfione, never met the guy, but the various interviews I've seen with him just give me that "used-car salesman" vibe.