I got these to replace my Sennheiser HD280 pro's. I use a closed back headphone when the missus is in and the tv is on.. Although I still like the 280's and rate them highly, I was never happy with the bottom end frequencies and would spend most of my listening time playing around with the sound before I could relax!
The ATH m50's have no such problem with lower frequencies, infact the lower end would be my selling point for these with every low end nuence being picked up without sounding false or coloured. The mids and highs aren't as prominent as the 280's and offer a more refined sweet sound. I also own the sennheiser HD650's and the sound of the m50's is closer to these because of their natural and fairly open soundstage.
I listen to classical music and appreciate uncoloured detailed sound. I also prefer a little warmth rather than hardness and thats what these closed back headphones deliver. Very comfortable, not too tight and with good isolation (not as good as 280's for keeping sound out, but much more comfortable)these are the best closed back cans at this price by far.