I like the BK-14 as it's easier to sharpen than the BK-24. I own both. I have TKC scales on the -24. I will probably buy some for the -14 at some point. I generally prefer scales regardless and don't care for paracord wraps in general. They get dirty and I would be too lazy to re-do it. Takes skill too which I lack. Don't own a BK-11 as I just didn't care for the handle shape when I was comparing in a store.
Frankly, it's hard for me not to choose the White River Backpacker Pro these days as I like the sheath and generally just about everything about that little knife I believe the blade steel is thinner too (at least thinner than the BK-24).
Added: The BK-14 and BK-24 were the first "neck knives" that I actually liked other than the little Dozier Canoe model. The Blackjack 155 is one I liked "on paper" but after playing around with it, I would rather carry a Becker. I do like the leather sheath on the 155 however and one of the few I would actually wear around my neck.