I have Delica's in VG10 , ZDP189 , Hap40 and Super Blue .
I carry a Delica everyday and have done so for quite a long time now after making a conscious decision to only buy Delica's and Delica associated products .
I work in a rural type setting and my Delica's get used for everything , they get covered in grease , dust , dirt , grit .
They cut rope , rubber , plastic , scrapes surfaces and anything else you can think of .
I don't remember the last time one of my knives cut paper or cardboard which seems to be some kind of standard to judge all others by , my working world doesn't encounter those things very often .
For this broad range of use the Hap40 steel out performs the others without any dought , no question , case closed , turn off the light on your way out .
It isn't the best at any one given criteria ( edge retention , ease of sharpening , rust resistance etc ) but it is the best compromise of all of the steels offered so far in my opinion .
You need to get that Hap40 Delica out of the cupboard and never look back
Ken
PS. - just remembered the last time I cut paper , Hap40 , push cut , one motion .