Cons: Not really portable(but I don't care), ear pads
From the various headphones I have owned my favorite till now has been MDR-V6. I have the HD-25-1 II as well and from the perspective of sound they are very good but I am not a fan of on ear headphone. I like them to cover my ears completely and somehow, the HD-25 I II make me a tad uncomfortable on a longer listening session.
I was researching regarding MDR-V6 upgrade and read a few recommendations regarding MDR-7509 HD. I posted a WTB classified but didn't get any responses. Furthermore, in India its impossible to find any good headphones.
I was casually browsing through ebay India website and saw the listing for 7509 HD, the seller supposedly had 10 pieces and was offering them for a price of $71. I didn't wait and ordered them immediately. I received the headphone today and the packaging looks authentic(the plastic box had the satin cloth on which the headphone was resting).
Also, immediately after I ordered the seller bumped the price to $107. This was last Thursday(23rd August). I checked now and he has bumped it up to $133.
I have been testing it for a few hours now and I am impressed and happy. It has all the positive qualities of V6 like good sound stage (for a closed can) and clean sound.
However, the deficiencies of V6 have been addressed.
I had the V6 and ZX - 700 and both of them had some issues with screeching mids. For certain songs it would become quite unbearable and tiring. This however doesn't have the problem.
The instrument separation is awesome. The mids and highs are good. The sound stage is pretty much same as MDR V6 and the bass is good too. I am not saying these have brain shattering bass but if you have heard V6 you would know what I mean. It has the thump to satisfy an average music lover.
I like metal music and don't have any complaints so far. The ear pads are crap but I have modded the DT250 velour earpads and installed them which now make this a good headphone for my taste.
I have been testing it through my Cowon C2 till now.
Once I spend a few weeks with them I will update this thread with more insights.
P.S. I have written to Sony asking them to verify its authenticity because I couldn't believe the price and my good fortune. However, even if its a fake it is a seriously well made and good fake.