I just got these phones delivered a couple of days ago and have enjoyed burning them in and listening in intervals all weekend.  They seem to benefit quite a bit from burn in, as most headphones do. What length of burn in time optimizes them? I don't know, but hey have improved all weekend.  They didn't sound bad right out of the box, but the extension, clarity and sound stage across the spectrum have all gotten better with each hour of burn in and listening time. They are very accurate, open and transparent sounding to me.    Some reviews I've...