Does what it's namesake says, sneak attacks hurt ALOT. Think about it, if you come up behind someone with a longsword and jam it into their back, they will fall down, I promise you, just don't try it at home, but ask anyone thats ever been impaled with a longsword what happened, if you find any living... If a twenty five pound test bow can explode an apple at several yards with a even a thin tipped arrow, then if you are standing three feet away with a longbow, which is a lot more resistance than that, with a weighty, thick arrowhead on it at you shoot them with it, what do you expect to happen? The WILL go down and not get back up again. This may be overpowered at 30x damage, but it gets the point across. It will imbalance the game's challenge, so use it for its purpose, the adding of a killing blow to the game that is a bit more realistic than a 60 year old lady with 10 or so arrows sticking out of her chest running around and fighting effectively. I will later release a mod that ups the damage and things for getting the fact that getting hit with a 30-45 pound steel claymore in the ribs does a little bit more than chip your health bar, it sort of cuts the hell out of you, and so it doesn't take 35 slams with a daedric longsword to kill someone.