Pros: Excellent sound quality. I'm not exactly an audiophile, so I suppose I'm not as qualified as some to make that judgement, but they're bloody good for my purposes and better than any other in-ear phones I've owned. (And if you are an audiophile, what are you doing shopping for sub $5 earphones? eh?)
Noise isolation is also brilliant. I've yet to wear them outside but I can't hear my PC with them in. this is quite some achievement seeing as my PC sounds like a plane taking off.
The build quality is pretty good too. they're made of metal and they look nice (in my opinion at least - btw its hard to tell from the photos but those are just silver dots and not the tacky plastic "crystals" you get on these sometimes). what more could you want?

Cons: Cable isn't the greatest. the rubbery material you get sometimes would have been better (and I've seen it on cheaper earphones than these).
They aren't the cheapest on DX either, but I think that's more than reflected in the quality. and its only a dollar or two difference in any case.

Other Thoughts: Not sure how the other phones from this manufacturer shape up. might be nice to have a bigger selection of their products on DX if they're all this good.
I'm also completely unsure of the purpose of the thing on the cable with the lanyard sticking out of it, or indeed why you can unscrew the end piece, but maybe I'm just being stupid.

Bottomline: By far the best earphones I've got from DX, or anywhere else for that matter (not that i've owned a great deal of high-end ones, but they certainly kick the crap out of my $30 pair from a certain leading japanese electronics company)