Wow, that's surprising to hear. Actually, on my graham slee diamond the T1's are pretty smooth up top too - smoother than the d7k and ultrasone sig pro.
I guess the final question if I may ask is which of these too, the T1 and the TH900 do you think sounds better....
...I know that they are on different lines of headphones and therefore it's hard to compare them, but if in 100 occasions you had to pick one to listen to on a random day, which would you choose >50 times?!
Thanks a lot for your answers - it's definitely helping me out and i'm sure others too.
If i had to pick, it would overall be the Beyer T1, but you better have a proper amp for them, that's the only caveat.