Col:
Actually, I rarely use either form of the word, I was just elucidating.
More often than not, I would use disparaging Yiddish terms such as schmuck or schnorrer. Or one of my favorite insults: Es ist besser du soltzt diener Kopf in Drerd schtecken vi a tsibbik. Rough translation: You should stick your head in the ground and grow like an onion; for you it would be an improvement...