I acquired a pair of the first my mk1 (MDR1000X) a year after the launch. Then I bought the mk 2 a year after the launch (WH-100XM2). I then started alternating because I was allowed to wear headphones at my job, battery life vs. volume, and I basically live in these things. Seriously people think its weird to see my ears. Now the mk 1 and 2 give me ear pain where I start placing the back cushion on top of the curve of my ear cupping them to my head after about 5-9 hours of straight use. I used them both in a factory setting at about 125 degrees (so i would sweat A LOT) and out and about; so they do stay on your head as long as you are not whipping around. The sound quality has never declined and the pads are still perfect; in fact I have dropped them and thrown them about usually onto things like beds or couches and there is really no visible signs of wear or damage of any kind. If not using them put them in the case they give that is also of great quality. It might seem like a hassle at first but it's worth, it's second nature in a short span, and will greatly improve the life span. Now with all that being said the mk4 are on the same build quality only better tech and lighter. Also the ear pain is no longer an issue and somehow the mk4 are more comfortable. The range now is insane, and until you test them it's unbelievable the area of movement. These beat out bose 35's no question. Now at like three times the price point, are open back, so the soundstage is different, are in 80% of the sennheiser 700. The sennheiser requires (when getting to this price point) having an amp and or a preamp to get the quality that they can provide. If no pre or amp the mk4 are on par or better. The 700 is about where the law of diminishing returns on headphones sound quality vs price starts. Now when compared to the Sennheiser 800S there is no competition and the mk4 are decimated.. however they are 1700 and have to have the extra equipment to run them at another 200-1000 or more, and they are wired so tethered to one place even if springing for a 30' cord at 100's or more.. Lost these headphones in a fire. Super sad face. If wondering I am also a working and paid dj, (but not now covid). So not necessarily and audiophile but definitely and enthusiast. My only complaint about the MK4 (WH1000XM4)is that when I am on a website like Facebook I can hear when the site is accessing the microphone in them every couple of minutes to listen. I do not have this issue with the mk1 or mk2. Facebook stop being creepy and weird. I also use these for League of Legends so I use both the sound and mic in team chat. The mic is better than average but nowhere near something like the antlion modmic 5. The Mk4 seem to be the most bang and the best bang at the price point. Literally the best sound and build quality until at least double if not triple the price point. I am and have been shouting this from the rooftops! I cannot recommend the Mk4 enough to every and anyone. Unless that baller stat money to blow, and want to be tethered; then the Mk4 are literally the only headphones anyone needs.