Hard to compare such a different constructions - closed vs. open.    Warmer and less treble glare = K550 for sure. I used them for just a couple of days, but I love them - one of the best closed back cans I ever used. But for me K612 are just superb in terms of clarity, dynamics, details ...   

  Factory is disconnected from the serial number. SN of mine is 360 - made in Austria.  

And here is my review: http://twojepc.pl/artykuly.php?id=Test-Recenzja-AKG-K612Pro&jedna_strona=1   the text is in Polish, but I presented a lot of detailed photo shots there as well.  I can prepare some kind of a gists in English if you wish. 

Yep, you're right, at first I thought that the artist got a custom model, but no there is exact this color scheme in stock: http://www.krugermatz.com/en/products/km0665mp   Even the webpage turned out to be in English now, 2 days ago it was in Polish only hence the link I pasted in previous...

OK, let me contribute a little bit to this thread with some decent quality pictures of the nice headphones ...          I think I'm in love in her ... 's headphones:    

    Ha! I found them!   Kguger and Matz KM665 http://www.krugermatz.com/sluchawki/km0665rw/ Looks like it's being produced by some Polish company, I don't think they are available outside Poland, not yet at least.  Price: 250zł = 60EUR / $80 Finish: wood, steel and leatherette. From...

OK, so that's me and Creative Aurvana Live!2 @ the office.       

  This would explain why they put a poor sticker on the K612 Pro, not a nice printing on the external earcup. Mine are 000360.   

Guys, I was asking seriously, what headphone model does the Polish girl wear?  The logo is blury, but it's long - to me it looks like Beyerdynamic ...    and here is Brainwavz HM9

  I burned mine for over 70 hours straight, I don't know if the sound changed enough to spot the difference though.    'Made in China'? You mean your's aren't made in Austria? On mine there is a small sticker on the leather headband. And the sticker is rather a silly thing when we are talking...

It was intended to be a parody video clip, came out to be a no.1 hit in Poland for a while :-)  The big advantage of this is that you don't have to turn the audio on :-)

What model of phones is this?            http://www.youtube.com/watch?v=rr1DSgjhRqE     Just fast forward to about 0:45 and start watching from there ... a little treat from Polish girls :)