OK I owe Sennheiser an apology. I really needed to play with ALL of the features of this headphone more. I will have to update my review to include all of the features and more real world use of those features.
The latest feature I had not actually tested was using the USB cable as an audio cable. I was working away at the office and decided to see how it worked today. All I can say is this feature kicks serious @$$. Suddenly I have a lossless format that charges the headphone while I listen to music, it sounds even better than the already excellent Bluetooth and it is fully functional with all of the 550 features including auto pause when I take the headphone off. It also gives me a more robust and fool proof way to use the headphone as a headset in that unlike BT which is finicky with communication applications USB is bullet proof. Did I forget to mention I can still be BT'd to my phone while using this with USB to my computer? so I can answer my phone while listening to music on my computer through USB, while charging the headphone, and it will auto pause the music on the computer while I take the phone call.
As I continue to delve into the depths of what this headphone offers I can't help but think it bests ANY other ANC/BT headphone at this point in time including the heralded Sony MDR-1000X which is the current Head-fi darling. Even if the 1000X has better ANC, unless that is the only requirement a person needs I think the 550 equals or bests it in every other regard except for maximum volume level. If you then add in all the functions and features that the 550 has that are missing on the 1000X I think the 550 is simply a better option for most people.
I'm not suggesting people sell off their 1000X if they have already bought one but I do think that Sennheiser is getting the short end of the stick in the ANC/BT war right now.
Actually I can even understand why this is the case. Sennheiser has packed so much into the PXC550 you can't easily appreciate what is can do even when you use it regularly. It takes time and need to really see just how much it does. It's kind of like sports cars. You can have an American sports car like a Corvette and compare it to something like a Porsche or (insert exotic car name) and on paper they might stack up for most big features. But only the person who owns and uses the cars daily will learn to appreciate ALL of the features each car has to offer.
Edited by dweaver - 12/14/16 at 2:33pm