good stuff.  Thanks all for your input.  I actually found a local store where I can do audition the cans with my own music and amp.  I will bring my HD600's and HD650's to pit against the T90's.

Hello everyone.  I have been searching the internet like a mad man trying to find out what the opinion is between both cans.    Current Equipment: I own the Senn-HD650's and the BD-DT990Pro 250.  I amp them from my Asus Xonar Essence STX Sound Card and both sound amazing.  I also have a Fiio...