Impressions after about 50 hours of burn-in, mostly unattended, so psychological burn-in is not that much of a factor:
1. Faster low frequency, especially important for anything that has powerful bass, in my case dubstep-derived genres. Attacks more abrupt, releases less reverberant, so quick succession of activity in LF range produces more powerful and engaging effect.
2. Change in HF that is more difficult to describe, maybe less harshness and silkier reproduction, I still feel there's a bit a lack of the frequency that benefits the sparkle ofsignature clean Stratocaster timber, most likely just under 5k mark. The only complaint I have about IT01 at this stage, of only they had CH9T's sparkle (although I find slight relative uplift in upper range of HF quite pleasing).
3. Soundstage. Subtle yet to me most profound, with the right source (both music and DAC-amp), soundstage is not only wide, but also layered, reverb tails are natural and mostly I have this nice feeling of encompassing soundstage, that has the dimension of its own, expanding in the outer world, rather then limited to the space between my ears or earphones. High quality sonic hallucination here!
But the musicality of IT01 is fantastic and enjoyable!