Just received my T1.2 -- at last. After only a few minutes of listening I'm very impressed already... compared to the original T1 treble is a tad smoother indeed, with a bit more bass just as previous posts stated.
Comfort is still very good with just the right amount of clamping force to sit securely, the color of the pads seems a bit more gray than the older T1 pads, which were simply black. This may be due to a slightly different surface, with the new pads sporting an even finer structure.
The new cable looks and feels very good, the plug with the Beyerdynamic logo in grey is a nice touch. The new case does have a carrying handle at the top (indentations where one can hold it easily) just as
@hanselmann said. Its still rather big, but nowhere as big as the old aluminium case. The ends of the headband are not metal anymore, but the extension mechanism feels better (though the DT1770 is even better in that regard).
Nice outer packaging, smaller than before:
The indentation described above. The front is indented as well, but much less.
Nice and decent logo placement:
It does keep open, but not by much... i.e. the lid may close a bit too easily to use this case for display.
The new cable:
Letz is the new one, right side the old T1: