Totally agree with you on this. Just the differences between the sound in different positions are quantifiable. Guess,they had to design the main driver and its positioning,in such a way that the differences are left to user's contention with his satisfaction! But atleast I think they should...

Probably due to different integrated dacs in both phones and also are you running these through Walkman app?or something else?

Just bought these,about three months back.Have to say they surprise me oftenly with their soundstage .And forward mids,are also the subject to be adored. Just like to share a thing about these.I find these headphones to be a bit on the notorious side,as for change in sonic character to change...