Omg, we're twins. I love my Beyerdynamic DT-880s. The only complaint I have is the impedance is very high, so their maximum output on most systems without headphone amps isn't very loud, but it's not like they're quiet or anything. Plus, higher impedance supposedly leads to a clearer high end (so audiophiles tell me), and I'd say that holds up to my experience with them. Sennhesiers, on the other hand, have never impressed me.
Yep, yep. AKG is just a bitchin' brand overall. Plus, almost all their products look super sleek and awesome.
Also, I used Sony MDR-7506 for a year and a half. They're very affordable and VERY good for the price. $75ish, if I remember correctly. You'll lose a bit on the lows and low mids when you monitor on other systems, but otherwise, they're winners.
For mixing purposes, isn't a closed back a bad thing (or at least not optimal)? There are minor reverb and phasing issues with early reflections coming off the ear cups of closed-back headphones. Or am I missing something? You've been around the block longer than I have, so maybe you've got some knowledge here I'm lacking But from what I've read, semi-open or open back headphones are the way to go for mixing in quiet environments.