My only criticism here will be on Active Noise Cancellation feature. Otherwise audio quality (if you listen without ANC) is good, as well as build quality, ergonomics, battery life. But then, (without ANC) you can buy a similar headphone at much lower price point.
Now to ANC : (after reading many glowing reviews and trying the product myself) I'm really surprised how majority of people can't correctly judge / describe what they are experiencing. A real ANC circuitry requires inverting ambient sound signal picked by microphones (on each ear-cup) and applying this to speakers. That process should never interfere with audio signal (your music) which is also driving the same speakers. So there should be two completely separate (for each L-R channel of course) signal paths / processing.
What this headphone circuitry seem to have is a "band-reject/attenuation filter" (tuned to around 60-200Hz, where most of real world rumbling exist). So instead of employing (such as above mentioned) separate noise inversion circuitry, engineers of Cowin must have opted for a much simpler band-reject filter. "Why" you would ask? Much cheaper to implement (fewer components). Yet it gets worse; they are passing the music signal as well thru that band-reject filter! How one comes to that conclusion? Simple; listen to details of your music crossings in such lower frequency region. Almost all reviewers correctly mentioned as; "you lose bass when you engage ANC". That's correct (as your bass range is below 200 Hz), but missing the critical design flaw. If you continue to pay attention; you (should) very quickly realize that also other dynamic elements of the song (in that frequency range) is fading in & out as it pass thru. It feels like there is a hole in audible range - and elements of your music (in that range) just disappear in that hole. That is simply that band-rejection filter butchering your audio. So design engineers must have opted out to use much cheaper/simpler chipset which gives the illusion of Noise Cancellation. One single signal pathway - cuts that low frequency band from your music AND some ambient noise from microphone. This is not real ANC and you get your music butchered. By the way; even if you try ANC itself (without playing any music); it's not really that effective.
There is a reason why higher-end Bose/Sony ANC headphones command a premium price.
BOTTOM LINE: When you read reviews as such "you lose bass when you engage ANC" simply run for your life; you are looking at another pretend-to-be ANC headphone with cheap circuitry.
For the reference; I did all my testing by playing FLAC files (lossless compression), to make sure that the source is pure.