Pros These things are cheap cheap cheap and sound wonderful, and are quite comfortable on my ears. Extremely light, too. They are the best-sounding supra-aural headphones I have ever had experience with, actually.
Cons Cheaply constructed, break easily. Short cord.
Summary For cheap headphones, these things can't be beat. I bought 10 pairs of them because I liked them so much. Many of them broke, or got lost, or got "lost", or given away because everybody liked them so much, and now I only have two pairs left. Maybe it's time to buy a few more pairs... I use them in the studio as a good reference pair, I keep a pair in my bag, and I used to have a pair at work, but I'm not sure what happened to them - I probably loaned them to a student who never brought them back. Anyway, buy some. I can't see why you would ever regret doing so, since they're cheaper than a McDonald's hamburger and sound much, much better :)
Pros Price point.
Cons None relative to cost.
Summary It sounds just fine if you're not expecting a Dr. Dre experience. And I'm not going to scream if they die. Super light-weight. Perfect if you're working out and you cannot stand sticking jelly-things in your ears. I imagine great for kids with this price point. Six months and they still sound fine. It's good to know that a quality utilitarian product doesn't have to cost a fortune. Kudos Panasonic.