David Broadwell LDC-107 with a very well heat treated CPM420V blade.
Spyderco Wegner without the hump, clip on other side of handle such that the curvature wasn't "backwards" in my front right pocket, and with the clip nearer the butt of knife so it didn't stick out of my pocket so far, in 420V, and lightened up weight-wise without compromising handle strength much, and with a more pronounced semi-skinner profile.
BM 710 with slightly thicker blade stock and ground similarly but with a stouter tip, and just a bit more of an index finger "guard"... and let's do it with "stainless 3V".
Emerson Mach-I without the single sided final edge, or at least with that edge on the RIGHT FREAKIN' SIDE! And with a clip designed for the Mach-I handle, mounted so 1" didn't stick out of my pocket.
Oops. That was more than "one change" on more than one knife.