Edge retention in blade steels is very subjective. Almost no other aspect of a blades performance is as affected by the power of suggestion.
If you did scientific blind tests of blades steels in actual use,you would find some shocking results in terms of folks "impressions" of how steels hold their edge vs the actual steel compostion. It's a lot like various vintages of fine wine. If something is LABELED as somehow being superior, then you will THINK it is even when it's not. It's more marketing than actually reality.
A Case in point look at this graph of the composition of AISI 440A vs Sandvic 12c27 and 420HC-
http://zknives.com/knives/steels/steelgraph.php?nm=440A,425M,420HC,12C27,AUS-6A
In almost EVERY element in the composition of those steels , 440A comes out on top. And yet, amoungst the talking heads in the knife world, 440A is thought of as being "inferior" to a "fine" European blade steel like he Sandvic or say Paul Bos treated Buck 420HC..
Well, if the steel composition is not to blame, what is? Could it be KABAR's heat treat? Not a chance in hades. They do 440A as well as Paul Bos does 420HC or the Scandinavians do their Sandvic 12C27. For example, folks sure seem to like their 440A KABAR next Generation USMC blades just fine...
To me, it's mostly all between folk's ears. 440A is a darn good all around blade steel . I'd wager that in a scientifically done blind test if the 440-A Remoras were labelled as being 154CM or ATS-34 it would "magically" hold an edge better .
IMHO,Other than obsessing over blade stock thickness, Blade steel composition is the biggest sales gimmick in the knife industry. Which is why there are so many different steels. Truly much ado about nothing. There are at least 25 Carbon and stainless alloy recipes that can make make great all around knife blades when heat treated and ground correctly. And guess what? they ALL need to be sharpened eventually.