I have a couple in my collection I haven't used. Some are SAKs that are destined to be taken apart for custom work if I every have a workspace. Others are my dressy ones- those get carried when I dress up, which is basically never, but on the occasion they are what I have in my pocket they are what I'll use.

If I get a Mk2 (thinking about it), I'll carry it. It might not get used as much as some of my other knives, becuase I wouldn't keep it in the truck and most of my off the blacktop trips are kind of off the cuff, but for planned trips it might just make me leave the Ka-Bars at home.