Build Quality & Design
The build quality on these isn't so good in the long run, the entire headphone is mostly constructed out of plastic the only metal part on these cans would be the earcups, when it's held in the hands the headphones do feel a bit flimsy and light; because of this they gave me a bad first impression at first, but i got used to it. Its not so bad once you get used to it. Now my biggest complaint about these headphones deep down in my heart, so sincere, THEY SCRATCH EASILY, when i say that they scratch easily "THEY SCRATCH EASILY". The second day I had them they scratched, now you must know, I treat all of my headphones with care, i've never scratched any of my Headphones. These were the first, this is my biggest gripe about these cans.
Now the design on these headphones were pretty good except for some cheap plastic parts on the headphone. but the look of this headphone is pretty good i must say especially in red. In my opinion these headphones look fantastic. But i wish that sony could've made the earcups a bit smaller, because when your wearing them the headphones look weird on the head, the earcups stuck out to much to the point that you don't want to wear them in public. Besides that i'm pretty happy with the design and look of these headphones.
Comfort
These headphones are very very very very very comfortable no complaint besides the fact that your ears will get sweaty after half an hour worth of music listening. Due to the fact that that the earcups are not very breathable.
Accessories
Sony supplies you with everything that you really need with so no complaint there.
Audio Quality
Here is where is gets interesting, now the Sony mdr X10 has a linear frequency response. The Lows hit so low and the bass sounds very deep, and its the best bass i've ever heard from a headphone, besides the audio technica ath m50, but the bass on the mdr x10 sounds very good. The midrange sounds very good just needs to be more forward. The treble isn't the best i've heard, honestly the treble isn't very good at all. This is what these cans lack the most is the treble. If sony increased the treble just a little more, these headphones would be fantastic. But they're not, but they sound pretty good.
Value
So these headphones used to be priced at $300, at this price your paying a little to much for what your actually getting. But recently Sony has a sale for selling these cans for $100. At this price it doesn't get any better than that, its basically a steal to what they're priced at. So at this price for $100, its very well worth the price.
But really, a headphone endorsed by Simon Cowell?! I'm willing to bet he hasn't seen these, considering his taste for beautiful cars. I'm also willing to bet that he hasn't heard these, because you know how he complains. And I'm willing to bet that he hasn't used these professionally, since he most likely would be using the (wait for it) Sony MDR-7506.