IN SHORT: A wonderful pair of headphones, and I cannot imagine it getting much, if at all, better at such a low price, but there seems to possible issues with build quality.
These were the first headphones I bought following a period of research and an attempt to find a pair of headphones for someone who really cares about sound without 'breaking the bank', and I can happily, happily report that these are exactly the ones.
For comparison, before this, I used the trusty Sennheiser HD 201s for practically as long as I have been using headphones. That is to say that I cannot compare these to any of the 50+ euro headphones for sound-lovers out there, but rather to the mainstay of 'relatively cheap headphones'.
I care a great deal about soundstage and detail, and these offer precisely that. 'Delicate' sounds like harpstrings are rendered wonderfully and without any muffledness. Even amongst a blossoming 'midrange' or bass, details (such as background vocals or instruments) are not lost. Bass is satisfactory and midrange wonderfully rendered.
They are also very comfortable, and come with the 3m-cable (in addition to the 1m one) that is so important to me (as I often move a great deal in my room with these on). The added pair of soft earpads are also wonderful.
My one and only complaint is that I have gone through 3 pairs in which one ear has gone deaf. This is despite care and attention. HOWEVER, I MUST stress that Thomann has sent a replacement every time, without any hassle, and that I have nothing but praise for their customer service. Still, I don't think I'd buy these from a place that *doesn't* offer 3-year warranties or easy replacements for broken products. All three of the aforementioned deafened after two months of normal desktop use; however, my fourth pair is currently on its fifth month of use, and so far I have had no issues.
So as summarised in the beginning, they are a wonderful pair of headphones - especially for the price, provided you're getting them from Thomann or from somewhere else which allows hassle-free returns and replacements.