First off, let me express that I'm not limited to just the T1 as an upgrade, but my focus in this post is understanding the similarities/differences between the two, and if it would be a suitable upgrade for me. That said...
I have owned a pair of Beyer DT770 250ohm's for about 8 years now. I recall ordering 6 different pairs of mid-high end headphones from different companies in my quest to find "the one". I was at the time a complete novice in audiophile lingo, and was fooled into think $ = Quality. My mind was blown when that 6th pair, which was my 770's, came in. I remember closing my eyes and forgetting where I was in the world, wrapped up in audio bliss, and being puzzled why a $200 set of cans sounded so much better than the $600 pair of Sennheiser's I'd just sent back.
To this day, my 770's are serving me well. However with the time I have always wondered if there was something better. I've been slowly upgrading my hardware over the years, and I'm at the point where I would be willing to go all out and say to heck with the cost, I want the best I can get, so I can enjoy my tunes with that peace of mind. \
I spend the majority of my time in front of my computer, so when I decided to buy a quality headset to game with, I read a nice set of reviews with the majority of them comparing it to the DT770's 32ohm version, and was sold instantly. But when I got them, and even still, they sound NOTHING like the the 32ohm version. They're exceedingly flat response curve, which I later found Beyer did intentionally, was more oriented to letting you hear things in a game environment rather than a musical one. Once I EQ'd the living heck out of it, I came to a sound that was similar to my 770's, but lacked that soundstage I so desperately crave.
Because I have grown very attached to the Beyer style signature, my preference is to stick to Beyer headphones if possible. After my aforementioned escapade with my MMX300's, I'm also now weary of many reviews I read even about Beyer's products.
I listen to a varied array of musical genres, but my primary crutch is Instrumental Progressive Metal. Bands such as Scale the Summit, Animals as Leaders, and the like. I love how I can hear something for the first time, then listen again and hear something completely new because the quality of the DT's is so impressive. I play a drumset as well as a bass guitar, so I fell in love with my 770's initially because I wanted to be able to not only hear each instrument as a separate unit, but for instance on the drums, Hear every single cymbal as if it's own instrument, without having to pump up the treble and have everything else heard as well. I on even some recordings, if they mastered it correct, can tell in which way a cymbal hits the stick, and I want that type of quality if I'm to spend the 1ishK on a T1 Tesla set...
Now that I've described what I have, and what I'm looking for in a premium set, I ask would the T1 be a good upgrade for me? I want that lush texture the 770's bring, so i can enjoy listening to that aspect, as well as be able to enjoy hearing the complexity of these band's recordings in full detail.