I have the CQC-2K and 4KXL, the 2K is pretty tiny and doesn't do anything specific really well but is still a fun little knife. My 4KXL is well put together, good fit and finish, everything is centered. Overall it's a good knife and it's part of my EDC rotation now, worth the money. The 6K seems pretty good too, but how about a 6KXL, Kershaw?