Wonderful Headphones
For the price, these headphones are quite a deal. If you are looking at them I would strongly recommend buying them, but also look at some headphones like the Beyer Dynamic Custom One Pros or DT770's that are in the same price range.
Where do I start? -Build Quality is excellent; The headband is very flexible, all the pivot points and rotation points are very solid and work great; This is made mostly of plastic, but it does not feel like plastic; -Features are plentiful.
The one minor detail I would mention is the amount of padding on the headband is a little less then there could be; It can be uncomfortable for a month or so until you break them in and get use to wearing them.