I have NEVER had more comfortable headphones in my life, and I've worn many. They are on the heavier side (more on that later), but they do not feel like it.
Even after 8+ hours of constant use my ears do not sweat and temples of my glasses do not feel uncomfortable, at all.
Sound quality is very VERY detailed, you can hear every smallest little thing and it seems there's very little cross modulation of frequencies, and even though the frequency response isn't completely flat, one can make very accurate mixing decisions. And if you need them to be more flat, you can just put very small shelf on the top end that brings higher frequencies down a tad (1-2dB or so). Bottom end is solid without being at all hyped. It's all very well balanced and they can be used for real work.
They're really easy to drive, even weakest of headphone outputs can make them loud and using a proper amplifier, you even need to put some attenuation on the input side to get proper adjustment range, this could be a negative to someone, but in my environment, it hasn't been an issue yet.
The build quality is very high, they're almost completely made of metal (aluminum) and there's no plastic in any part that takes constant abuse, like hinges and ear cups. All the foam is replaceable and even the memory foam on the headband is attached with Velcro for easy replacement or even removal if you prefer it that way.
Attenuation of outside noise is high and attenuation of cable noise is quite adequate.
Only "negative" I can imagine is, that they do not come with a carrying case to protect your investment, but ~20€ for one isn't much and the carry case is of good quality.
I wish Austrian Audio would bring the locking 2.5mm connector available as a DIY part so one can create their own compatible cables for situations where the available ones are not enough (extra long, coiled etc.)
The connector isn't unobtainable, but it's not common either.And in a pinch, you can fit just bare 2.5mm connector without locking mechanism and it'll work just fine.
Overall, very high end headphones and considering everything, price is reasonable.
As long as Austrian Audio keeps the spare parts available for the decades to come, these will be a forever investment for one's studio and even for just enjoying music.
