if isolation and clarity are important

I auditioned many different sets of headphones, my criteria were ISOLATION(ie. for using where there is a lot of ambient noise to block out such as on a plane, or also where you don't want the sound bleeding out of the phones to bother other people nearby) and CLARITY (obviously wanted the best possible sound quality).
While an open phone design can generally present a more detailed sound stage (such as grado 225 headphones or better, being an "ideal" case), of the closed designs I tried out ranging all the way from $80 to $300 (including ultrasone, sony *yuck*, sennheiser) this is definitely the best of both worlds and comes fairly close to the grado for detail (wow!). Quite an achievement.
Very solid and realistic sounding bass (but can be a bit overpowering), nice clear mids and present articulate highs, no harshness.
My mp3 player and portable DVD has no trouble powering these headphones.
They are very well constructed, the cable and other materials are robust, much better than others in the price range.
Can easily be folded up for travel.
Extremely comfortable to wear and can be used for an extended period.
RECOMMENDED!
Audio-technica has combined various components of great engineering to create what I am sure will become a staple in many studios for quality monitoring, and at this price it is a great option, if not the best option for home entertainment use where sound quality and isolation are important.