The advantage of the T1.2 is going to be dynamic range, the imaging precision, and the overall smoothness of the presentation(the DT 1990 and Amiron are a tad rough up top in direct comparison), and just a better overall sense of cohesion and fullness/solidity. Soundstage is a bit bigger, the T1 focus is more on imaging precision and quality than soundstage width/size. That and the T1 does have better build quality and better durability plus a 5 year warranty vs 2 year. The Amiron Home and DT 1990 do have some points of failure, the T1 just doesn't have.