I have the Ultimate which has 250GB... I have 40GB left and 10 days before I get more... I'm going to be paying again for overages this month. It boggles my mind. If nobody goes over their limit, why have them in the first place?
I have 80g, am a gamer, 2 users, 6+ devices, and rarely go over 50.
For many people, it comes down to what your usage habits are. If you do a lot of p2p, torrenting, continual Netflix usage, you might go over.
I could never thinks of EVER using 250g like mbazdell, but again, every users usage is different. Bar finding a provider which will give you more for the same price, if you can only afford a certain amount, you have to adjust your usage accordingly.