They're excellent for the price - I've been using them for 6 months daily and they're holding up very well.
Ditto this. I previously had a pair of the Sennheiser CX 300 II - they broke within a year whilst being handled very gently. The SoundMagics are just as good in terms of quality if not better and more durable.
I found the build quality on the CX 300 II's to be very poor in comparison to the CX 300s. The little sennheiser logos came off the sides after a few weeks, and then the cable burst from the bud. Made the move to the E-10s and after fiddling about with the different plug sizes, found that the double plugs gave the best results in terms of comfort and perfomance.
Wee comfort note: If the metal casing rubs against your ears, try using the double plugs and turning the cables so they go up and over your ears.