Hiltslash is a way more annoying mechanic than polestagger, and IMHO more annoying than even "lolstab". Polestagger occasionally allowed a free hit after you had already gotten hit, hiltslash can be abused any time. 2h Weapons can hit for full damage in the first 1% of the swing animation, while they are still behind the wielder's shoulder. This is unrealistic and just looks silly.
Watch two pro longsword/HBS users on the duel server, and count how often someone lands a hit on an opponent that is actually in front of them. It will be a rare occurrence. Somehow I think medieval swordplay involved actually facing the guy you were fighting.