Some halfast thoughts before the big guns with actual experience show up :
I have no Magnacut
I have tons of S30V.
I have had the good fortune of buying ALL of my S30V when they got good at heat treating it.
Some will call : desastrously chippy on S30V
None of my S30V has been the least bit chippy
I get really great edges on it that last for me.
Really decent "razor edge" for me that last well enough
Not as "razor edge" as ZDP-189 (which I love to death) but ZDP can be chipped if one does STUPID things with it. I chipped it once and learned my lesson for all time.
You may want to look at this
web site / link ; page way down to STAINLESS STEELS.
Those tests show Magnacut is better at toughness but not edge retention by a small margin.
(sorry if this is a forbidden link; I believe it is not)
PS: the only reason I don't have any Magnacut is I live in the high planes dessert and have no use for stainless steel .
EDITED : to correct one of my stupid mistakes.