never seen a vorpal under 16, but I'll take your word for it.
and to reiterate, I'm not asking for a change in min level or max damage to kill. but on the damage dealt, and i'm really glad to see all the suggestions coming up for it. we have some good alt ideas here.

Now I can understanding that the 100 is only dealt on a 'failed' vorpal attack so yeah a failure may only get a little damage as compensation, but it's the things that are immune, that's where I'd like to see the 250-500 damage rolls, cause there is no chance for an instant kill anyway. without the chance of success failure is a moot term.