Wow, ok. This is my first review. I was in the process of trying to purchase a pair of wireless headphones and bought all of these and will be returning the ones that don't make the cut. I use a pair of LCD2.2 non fazor and a pair of neumann kh120 monitors as reference. The prices are as follows: PSB M4U 8 $399 NAD HP70 $399 Bose QC35ii $349 B&W PX $399 B&O H9i $499 or 448 in black Comfort PSB, somewhat narrow pads and fairly shallow as well. They don't weigh very much and clamping force is not bad at all. NAD, slightly larger earcup both in depth and width. Weight is not noticeable. The headband is round so the point of contact is smaller than the others. In addition due to the design, most of the mass is about 1/2 inch out past the earcup, when making head movements you can feel the cups moving a little bit. Bose, much larger ear cup than all of the others in this review, also probably the lightest. The clamping pressure is light but secure. very comfortable for long periods B&W, roomy earcup both in width and depth. Weight is about on par with the others except the bose. Clamping is moderate and suffers from the same problems as the NAD. With a small round headband and metal mass outside the earcup, they don't feel as stable as some of the others. In addition the leather cups come to an edge which feels slightly odd, like putting a cup over your ear, a very small area of contact. The B&W's come across as a hollow headphone with lots of bass. There is no air. Imagine listening to a headphone through a paper towel roll. Even acclimated, the bass is tubby and bleeds into the mids. I really wanted to like these, I think they are the best looking of all but there are just many better options. In short, style over substance. The B&O H9i are a fairly stylish modern design with round leather ear cups, a decent half round headband, and aluminum touch sensitive discs on the sides. These headphones come with an app that allows one to adjust between a few eq settings but I left it flat for this review. These are on the brighter side of neutral with of course some weight in the bass area. Imaging is ok, but nothing to write about. There is a moderate bass impact almost punchy. Overall a fairly well balanced headphone. One gripe I have is these will slide right off my head if i lean forward or backward with my head parallel to the floor. Bose, these are by far the lightest of the bunch by a considerable margin. Even though they are a closed headphone they seem to be able to convincingly convey a since of air and headroom. Again, another warm headphone. The highs can be slightly tinny on some recordings I am assuming with the boosted presence you either get an "airy" vibe or slightly abrasive top end. The mids are slightly recessed, with an emphasis on the lower end of the spectrum. My main complaint about these are their volume is not sufficient for classical recordings, I could listen comfortably to all of the other headphones at 40%, the bose for the same volume need to be around 60%. PSB, These are a completely new brand to me. Upon first inspection, they are well built, better plastics than the NAD, although still not at the same level as the B&W. These can be characterized as warm headphones with most emphasis focused on the midrange and bass. These are not good headphones for rock. They lack the presence and bass extension necessary to provide an engaging listening experience. But for a singer songwriter style or well recorded pop music they are fine. The NAD were a brand I hadn't had much experience with other than a cd player which came across as cheaply made. These headphones had a good designer, but manufacturing tolerances and assembly were given less attention. I am nitpicking here but some of the seams don't line up, and the plastics feel inferior to its peers. The NAD initially come across as bright and somewhat sibilant with weighty lows more pronounced in the sub bass region. Kick drums come across as tight and punchy. There is a v shaped response with the mids slightly withdrawn. Pianos are overly empathized in the low end but female vocals are fairly well presented if not slightly thin.