These deserve a thread here in the full-size headphone forum so I am starting this one.
For transparency sake. I contacted Sennheiser a couple months ago to see if I might be able to review this headphone. I received a loaner pair this week for this purpose. So I am not an owner of the headphone and these are not a free pair I received in exchange for a review.
Since it took a while to find out if I was going to get to review the PCX 550 I ended up buying the Sony MDR 100ABN, and Bose Quiet Control 30. Bad news for my wallet, good news for my review as I will have to high end models on hand to compare against. I am also working to see if I can possibly get my hands on the Bose Quiet Comfort 35 and Sony MDR 1000X to round out all the big contenders. But will work with what I have to get things started.
Here are a couple pictures I took as I unboxed the headphone. Unfortunately they show my lack of photography skills as much as they do the headphone. More pictures to follow.