I received two MK5s in the mail today. One for the kit and one for my pocket. I figure that if I'm going to stick one in my kit then I should carry one around (as EDC) for at least a couple months, so I'm thoroughly familiar with it.
My first impressions of the knives are very good. They feel extremely substantial for knives of their size. I have a buck Hartsook that is slightly too big for the kit even without it's sheath (it's way too big with the sheath), and the MK5s, although smaller, feel much more durable, robust, strong... The MK5 certainly feels much more like the type of knife I want in the woods (or the city for that matter) when something goes wrong which requires me to get into my kit for a backup knife.
They both came sharp enough to shave with although I reprofiled and resharpened the one that I put in the kit, anyway. Mostly I just did this so that the knife would have one of my natural hand-sharpening angles on it. I figure this way if the next time I sharpen it is after something has gone wrong which required me to get into my kit for a backup knife and use it to the point of needing a resharpening with the small diamond hone that it also in my kit, then it will have a profile that I know so well I could probably touch it up in the dark with one hand.
The only one of my first impressions that is not good was actually not with the knives at all, but rather with the sheaths. Both sheaths are extremely loose. I did the Coke Zero test and both sheaths failed miserably. Neither one would move the can even a little bit. But, I have emailed CRKT as per Doug's instructions, and now wait for a reply. For the record though, I used a can of Diet Dr. Pepper. I also did not disclose that information to CRKT, so they may think that I used Coke Zero!