With the $50 monthly overage maximum on Extreme, does that mean I can go over the 120gb limit by as much as I want, or do they shut you down at some point?
you won't get charged more than $50, and once you're over $50 you can go crazy and use as much as you want. it happened to me once where I was just about to hit $50 extra so I decided to grab as much stuff as I possibly could and used up 1.5TB that month.