well, i don't think its -EV. you're playing off of people's fear of your stack. they see your big stack, and figure you are a saavy player, and fear that you will be more willing to call and be aggressive and have a good hand than the average person. its more about using their fear of your stack to your advantage, than you actually changing your play, even though IMO that does happen a little bit too.

Keep in mind too, this is just my opinion on it, i'm sure everyone thinks big stacks have different benefits and penalties.