These are great headphones for this price, and they can often be found at a discount. I've used them extensively for the past few months and they have gotten better over time.COMFORT:Initially, they were a bit stiff and uncomfortable, especially the ear pads. They would make my ears a bit sore after an hour or two of use. After a few months, the ear pads and headband have softened up and they feel much more comfortable. I can wear them all day and not feel a thing. They somehow feel more comfortable than my Sony WH1000XM4's which are $300 premium noise cancelling headphones. The XM4s make my ears very hot and the top headband hurts the top of my head after a while. These WH-CH520s keep my ears cooler by virtue of them being on-ear rather than over-ear, as well as staying comfortable on my head all day due to their light weight.SOUND QUALITY:The sound quality on these is great for the price and size of the drivers. Out of the box with no EQ I'd describe the overall sound as being slightly warm but very accurate. They have a slight V-shape Harmann Curve sound profile, with very clear and present mids. The bass is clear and pretty clean without being too thumpy; not the quickest bass response I've heard though. The trebles are a bit recessed but pleasant on the ear. However, you can boost the treble up with EQ in the Sony Headphones app at 6.3K Hz by a few dB to get more detail. These are definitely geared towards general consumer use with a very slightly sound profile perfect for pop, rap, rock, edm, indie, podcasts, etc. However, I was surprised to find that the bass is very tame and accurate, and the mids are crystal clear and sit perfectly in the mix. At this price-point and target consumer I was expecting these to be very boomy and washed out sounding, but they are actually very balanced and accurate. They really shine in vocals, voices always sound very forward and detailed. In terms of sound stage, they're a clear step above any in-ear headphones, but they aren't as wide as a typical over-ear headphones, which is to be expected. Imaging is great and accurate, they do a great job accurately placing all of the instruments in a stereo mix. Overall the sound on these pleasantly surprised me and definitely punch way above their weight class for the price. They sound as detailed and accurate as $100 headphones. If you're looking for something very "neutral," these are your headphones. But with the EQ provided in Sony's Headphone app, you can theoretically have these sound almost exactly how you want.BATTERY LIFE:Battery life on these is amazing. They can last me around 4-5 days with around 7-8 hours of use each day. I use them nearly all day during work. They charge really quickly too, which is great.FUNCTIONS:They have a standard pause/play/skip/answer/hang-up middle button, as well as volume up and down buttons. You can skip and rewind by holding the volume buttons.They can also be paired with Sony's headphone app which allows you to change the EQ settings for these and have them sound how you want. There aren't a ton of sliders for the EQ, but enough for most people to customize their sound to their liking. There's also a fun custom EQ feature in the app that asks you to pick your favorite sound profile from various examples and builds you a custom EQ profile based on your taste.The microphone on these are pretty good for headphones. They sound better than average in terms of headphone mics, but they don't sound nearly as good as the iPhone 15's built-in microphone. But if you need these for a quick phone call or video call, they work great. They can't fold up in any way but the ear cups can swivel up. So if you take them off your head and swivel them to hang around your neck, the ear pads will face up; which isn't good nor bad, just something to keep in mind.EXERCISE:If you're the type to use headphones rather than earphones when exercising, these would probably suffice. They are breathable and lightweight, while also having a decent clamping force to stay on your head. If i shake my head vigorously though, they inevitably fall off. The earpads are a faux-leather so they're very easy to wipe off and clean. Although, I'm typically the type of person to use earphones while exercising. The most extensive exercise I've done with these headphones is skateboard with them, but as soon as I start jumping around to do any tricks, they start to slide off my head. They should do fine with typical gym exercises movements though, they won't slide off if you're looking down.NOISE CANCELLATION:In terms of noise cancellation, they are decent. They obviously don't have any active noise cancelling features, but passively, they block a bit of noise, maybe 10-12 dB or so. They aren't going to blow your mind though in terms of noise cancellation. However, if you have music playing at around 40-50% volume, they block out a considerable amount of outside noise like most headphones do. I can walk through busy downtown streets with these and not hear much at all if I have music going. They'll definitely block out a considerable amount of noise in an office, cafe, train ride, etc. so long as you're actually listening to something.BUILD QUALITY:These headphones are built surprisingly well. The materials are obviously cheap, but they don't feel like it. The plastic is lightweight, but solid at the same time. The earpads and headband padding are both the same faux-leather, which is a bit stiff at first but softens up over time. The padding feels like it will last a long time simply because of its synthetic nature.DESIGN:Taste in the way these are designed is obviously subjective, but I think these look great. They have a modern, but more timeless design. They don't look super retro, but they don't look super modern either. They just look like clean, standard headphones that will look great for years. I love how the Sony logo is faintly placed on one side of the headband. It's there, but not obnoxious.