I'm not an audophile like most of the folks here at Head-fi so I'm going to explain everything without using the usual lingo that 500+ post members use.
First, like dr_digits stated, they are solidly built. The pads are semi-circumaural like the 497/212, except they feel velvety. I spent 2 hours straight with them on and in my opinion, they are very comfortable.
The results were very different (but not bad) using my 3rd gen ipod compared to attached to my computer through my audigy gamer sound card. I found the bass to be more punchy using my ipod.
Here are the songs(at 224kbps) I listened to using my computer sound card at the headphone setting:
The following songs had very Clear treble. The phones handle bass well. They didn't sound muddy. The separation of instruments was good.
1) Tangerine Dream - Little Blond In The Park Of Attractions
2) Tool - Sober
3) Frank Sinatra - Summer Wind
4) Information Society - Pure Energy
5) Yanni - The rain must fall
6) America - Tin man
7) Ozzy - See you on the other side
If I was at a concert, I would feel like I was sitting about ten rows from the front. As a point of reference, the grado SR60 feels like I'm on stage standing in the center of the band.
At the price of $60 that I paid at newegg.com they are great headphones, but my pair of HD535 are far better sounding and the Technics 1200A handle bass much better.