I left wired headphones three years ago and have been Bluetooth until a few months ago. I’ve tried the QC35, WH1000XM2, B&W and Sennheiser $400 Plus Bluetooth headphones, and found the wired Sennheiser 569,579, 598 as well as the mdr1a, m100, B&O H6 all sound superior. I’m not an audiophile, but my conclusion must be it’s more than just driver differences, but wires. Some of these headphones are a third of the price as the best Bluetooth sets out today, yet are far superior in sound to me. Sure most wont tell the difference or don’t care but I can, and these 400 dollar headphones must have their money value for something other than sound. It must be paying for noise cancellation or dsp. Not sure but my $200 wires blow them away. That’s all I’m saying.