I don't really understand those graphs but according to joker, the CAL2 arent that bad http://theheadphonelist.com/initial-impressions-creative-aurvana-live-2/
Also, while I did say I liked the v shape sound signature, I'm now wondering if I actually do (although I definitely like that sparkle) cos I've been messing around with my EQ and found that everything sounds better (even if it's just a bit) with a mild 250-500Mhz boost (which I think is what people mean by warm)
I think I might order a paid of 770s and 880s and compare them, and just send the least favourite one back :P
edit: why is the 880 so expensive? Double the price of the 770 and 990 -_-
How likely is it that the 990 wont meet my needs/ leak too much sound?
I think that the 990 is too hot in the treble! the DT880 and DT770 have a v shaped sound signature, but the 990 is exaggerated (at least to my ears). The Dt990 will leak sound because is an open headphone, the DT880 is a semi-open headphone and leak sound too but in a minor way. The price depends of the country (in Amazon USA, DT770 250ohms- $169, DT880 250Ohms Pro- $189, DT990 250ohms Pro- $149)