anecdotal evidence suggests that Snowman is not sadistic.  although he is certainly psychopathic, he derives no pleasure from his actions, per se.  he does however  like the Punisher  derive satisfaction from the results:  fewer criminals on the street. 

unlike Punisher  who has consistently demonstrated a conscious acceptance that his immoral ends justify his immoral means  Snowman has demonstrated dissociative behaviors suggesting he has having internal trouble with his own conviction that the ends justify the means.  Snowman's own psyche is getting increasingly warped by his need  and inability  to reconcile his immoral actions with what he considers to be results any moral being would desire.

in other words, Snowman is a sick puppy and I'd rather face the Punisher any day.