I have a character in my novel who describes a creature's talon as "wicked sharp". My wife says this is something she would only hear in New England (and my character isn't from there). I'm from Colorado and have used this adjective all my life... But I also read a ton of Stephen King growing up so maybe I picked it up from him.
To be clear though, I would never say someone was "wicked smart", or "wicked fast"... I would only use it as an adjective when referring to something that also seems... Well, sort of malevolent, or wicked--like a creature's talon.
But maybe I'm just overloading / misusing the word?