I think this post will help you choose wisely. I found it in another thread. He regrets choosing beyerdynamic.
By no means am I Beyer fanboy,but in the past I have owned three different Beyer headphones:
T1
DT990 600 ohm
DT770 250 ohm and never had a single issue with them as far as them failing...i simply got tired of their highs.
Every headphone company releases a batch of headphones that have something amiss...heck Audeze has a horrid rep for driver failure and people still buy them...i own one myself...no problems.
To quote one members bad experience with a specific pair and equate that to writing off an entire company is....silly.