These are my first pair of 'studio monitoring' headphones, therefore my views on what sound qualities I should expect from them are unqualified. With that in mind, anyone reading my review regarding sound, should look at a review from someone more experienced with studio headphones. The primary use for these, is to not disturb neighbours during later hours, whilst having a decent enough sound (for me), and with both these in mind, the AKG's succeed.
Although I wouldn't consider mixing tracks in headphones, I found that balancing tracks' levels, was a lot more accurate than regular headphones to a very large degree. Hearing the same mix through speakers surprised me, as far as how close the two mixes were, level wise. I can't comment on EQ, as I don't think I can rely on headphones for that.
They certainly don't sound bad, and I have enjoyed listening to commercial releases, albeit with a flat EQ (I do notice that)
The problem for me, is comfort. The pads that are supposed to go 'over ear', press against the edges of my ears. After some time it becomes quite painful, because my ears get pinched on the edges. I don't have particularly large ears. From inspecting the pads, I can see that there would have been enough room to make the holes for the ears a little larger; that way, the pads would still serve their purpose of cushioning, without pressing onto the edges of the ears. I am considering enlarging the pad opening, if it is possible without ruining them.
Apart from that issue, I think they are good. The interchangeable cables are easy to fit, and have a good locking mechanism. The sound is good, albeit from the inexperience as described earlier. The build quality is good, based on the firmness of the headband, and plastics that I would expect at this price.