This is a question on if you prefer the character as straight up bad guy, or as an anti-hero type.
there have actually been some else world versions of Harley that have straight up made her a psychopath, like the justice league gods and monsters series (she's pretty messed up in that one).
Personally I've always preferred her as an anti hero type, she could save a kid from drowning, but as batman swoops in she smacks him over the head with her mallet.