I rotate through a selection. I travel, and work in varying environments, so I have to adjust accordingly at times.
I sometimes work in a couple of cities with silly knife laws (e.g. Chicago and Milwaukee) so I carry smaller knifes there. Also, some sissified office environments where only a small knife is acceptable. For those I rotate through some smaller knives (BM 707, Mcusta Tsuchi, William Henry E6).
Today I'll be in Milwaukee, and I'll be carrying a pretty-much un-flickable < 3" Mcusta Tsuchi. Next week I'll be in Indiana much of the week, and I'll be carrying a Southard or BM 940 to work.
When I'm working from home, I carry the Southard, a BM 940 or BM 710, mostly.
When I fly and check bags, I throw a Chinese cheapie in the bag (so I'm not sad when if a TSA employee steals it)--usually an M028, F723 or L01, depending on where I'm flying.