Yeah, Roger Stern did an amazing job on Monica (and with the Avengers as a whole during his run). And I think that's what C list characters often need... a writer that is willing to absolutely push that character as far as they can possibly go. Yeah, you get accused of being a "pet" character or whatever, but for non established characters that's what is needed to really establish them. She was absolutely great in Avengers during Sterns run. Shame it ended the way it did.