I have been using the more expensive HD25 headphones for 20 years and rate their sound and build quality, when I saw the light version was available now i bought a pair for my daughter to listen to music and also for monitoring purposes on her pc, then I got a pair for my partner as she needed some decent headphones for her computer for too.
The sound is pretty much identical to my more expensive HD25's and I haven't heard better headphones at this price. The build quality seems good as we haven't had any breakages yet, and as far as I know all parts are repaceable if anything does break. The sound is amazing and well balanced, bass is exceptional and volume more than adequate.