It can be either a good or bad adjective based on tone and use in a sentence. It has to be pronounced in the accent as well (Meeeeee-Tell)
Female version: Meesy (Meeee-Seeee)
Bad Use: What the fuck, you are such a mitel, you drank all my booze! Fucking mitel whore.
Alternative Use: That mitel is psychic. He is a psychic mitel.