Eh, 1000 or 1024 is pretty irrelevant, really--ALL the whoosis-byte labelling is fictive. You're doing *well* if you get 90% of the listed capacity as genuine usable space, so I just use the label capacity as a ranking method: I might not know how much it'll *really* hold, but 1 TB is bigger than 750 MB and smaller than 1.2 TB.

It's kind of like the temperature ratings on sleeping bags. I can guarantee you I'll freeze my a** off if I'm in a -10C-rated bag on a -10C night, but at least I'll be warmer than if I were in a 0C bag.