^ Yes they don't need much of burn-in since they are balanced armatures, Ive done ~20-25 hrs on these but not much change as such. There are things I love about these ,the soundstage, the overall fun sounding and musically engaging mids and vocals ..Even the bass is perfect with foam tips..
It's just the grainy noise / distortion at times which spoils the fun.I am doubting the badly encoded tracks are to be blamed ,though I am listening to all 320s mostly.:S.