You are saying the mid bass rolls of terribly, how will I notice (will I at all?) that as a listener with very little experience?
I have just listened to the standard Samsung earbuds, the Koss Porta pro and my Razer Megalodon (gaming headset) thats about all the experience with headphones that I have. (Have heard the Beats Solo and they seemed OK to me with this little experience (Wasn't all that impressed by them though, and know that they are extremely overpriced)).
The DT880 are way too expensive for me at the moment, I need something in the price class of Creative Aurvana Live and the Sony MDR-XB 700.
Mid-bass is more of the "mainstream bass" IMO. The Beats have a big hump in the mid bass, but roll off quickly in the sub-bass. The sub-bass is the lower frequency bass (generally below 80hz) and would be the bass that a dedicated home theater subwoofer would produce. This has a lot more rumble and eventually can get to a point that is barely audible but you can still feel the sound. I don't know what other cans you were looking at or your original post, but the Ultrasone HFI580/DJ1 would be another bassy headphones to look into.