Have you actually tried to use the whole TB? :) I think this deal is along the lines of "unlimited" internet that cable companies offer and "unlimited" hosting that many shared hosts "provide."
No, I haven't come close, I just got suckered in when I was looking at different hosting companies and they had the best numbers. One difference between them and other "unlimited" hosting is that I think they do mean it -- I asked them if they had a simultaneous connection limit or any of the tricks other shared hosting providers used to cut people off that use to much bandwidth and they said no.
I would switch to a $20/month VPS like slicehost that provides a tenth as much bandwidth but I don't really need to set up my own services at this point and I don't have much motivation to switch, though I really should before my startup is launched. Latency is kind of bad too, my sites just feel slow when they load.
