I'm actually glad you asked me about it because I just went back to do a/b listening of IT03 and A83. When I took my listening notes, some were taken awhile back even before I reached full suggested burn in time, I remember hearing upper mids (vocals) in A83 to be smoother and more organic (natural) in comparison to IT03 (IT03 was brighter at first). Now, I'm listening to both and hear them sound equally natural but IT03 has more body in lower mids in comparison to A83, making its (A83) mids sound thinner and a little more out of my head (you can call it a bit more distant). While I have been testing other DAPs in the last month, I had IT03 on a "burn in" as a load, so now have over 200hrs on it. I'm still very impressed with an impact of the bass, but the sound is more balanced and more coherent. What is interesting, I have been listening to quite a few totl flagships lately, and usually you can hear a noticeable difference in sound going from TOTL to other "budget" IEMs, but IT03 sound still holds up!