440C was a premium steel used by custom makers well into the 1980s.
Cast 440C is a totally different beast, don't knock it if you've never used it. It does not behave like "normal" steel.
In my mind, you'd be hard put to tell the difference between 440C, VG10 and 154CM (all properly heat treated for application) in normal use. 440C will take more abuse than VG10 and possibly 154CM.
Buck stopped using 440C because it was "too good", i.e. so durable it was hard to resharpen once some dingus got it really dull. They dumbed down their steel to 420HC.
When 440C was hot, Spyderco used to use Japanese manufacturers who liked Japanese steels, such as AUS8, AUS6, GIN over 440 series which is more "western."
440C as a "brand" got destroyed by the poorer performance of 440A, 440B and the use by many cheap factories of the no-name "440 steel." This created an undeserved bad rep for any steel with the label "440" because people often did not know the difference between 440 steels and thus damned all 440.
Benchmade's 440C is a superb performer, equal to their 154CM in my usage.