A BoomBox on your ears.

I walked into a J&R and a salesman showed me his personal pair of PortaPro's. I then proceeded to hook my iPod to the portaPro's. Whoa. I was sold like that.

Sound Quality:
The bass in the beginning seems uneven, and even a little bit exaggerated, but I began to find the definition of the bass compared to headphones in this price range ( < $50 ) excellent, uncomparable even to the closed-style DJ headphones that Sony and Panasonic sell. It's great for trance, dance, jazz, anything your iPod will throw at it, with a good amount of definition from the trebles to the bass. Of course, I'm not proclaiming you should use these over your Grado SR80's at home, haha but they are definitely the BEST buy if you are using it in conjunction with a low-powered MP3 player such as an iPod and constantly on the go.

Comfort:
I found that the PortaPro would "eat up" pieces of hair on my head. (i.e. my hair would get caught in the metal portions) Hahaha, yes, that's why i despised 80's styled headphones and that's why manufacturers have been putting plastic or leather on the head since then. Of course, since then, I have been wearing my portaPro's behind my head, 90's style, and have not suffered from this problem since. Also, the Koss's come with a "comfort" setting but have found it to be of little use.

Aesthetics:
Well... Yes, to be honest, these look dorky. There's no way around it. But hey, when it's on your head you can't see them anyway!! hahaha, the portaPro's come with a leather (perhaps?) carrying case, and a headphone jack converter for home use. The PortaPro's also fold very nicely into a ball, and portably, unlike other headphones.

Durability:
My first pair lasted about a year, I wore them daily from my daily commute to Queens and back to Manhattan. If i popped a speaker off because I dragged the cable by accident, it was easily reattached. I finally broke my first pair by sitting on them, breaking the mount. Supposedly there is a life time guarantee, but eh, on Amazon, the price was ridiculously good and bought another pair.