I'd arguably say the DH's, since they're not bereft of their souls the way that DK's are, and the DK doesn't have a permanent demon in their brains, trolling them and otherwise mentally straining them at all possible times.
And how I saw DK's in the beginning of Legion, they seem very nonchelant about very amoral stuff...so giving up their humanity absolves a lot of the mental beggage they may have had before undeath...i.e. they don't really care all too much. They may be aware of it and not care, while very few of them actually have feelings about it, if they have feelings about anything at all.
DH aren't done sacrificing, it's an on-going process, and they have sanity, soul and body on the line constantly, while DK's are relatively 'free' to do what they please with very little drawback to them personally...and they can probably kill demons without sloberring over them as well because they get hungry.
I have sometimes wondered if demons are considered fast food for demon hunters, and every kill is a snack on the go...just grab a few bites while they're slicing and dicing it anyway, then onto the next. Is their fighting style considered culinary arts?
I'm clearly on too much wannabe-sugar atm and should get some food. >_>
They're not really dead anymore, they're undead. Also my DH died in the prologue, sooo...I win? Actually, that'd technically be a draw, since DK's have to die, but they didn't die willingly, so not really a sacrifice, more of an enslavement, while DH's are willing to die if it means getting closer to ending the Legion for good.