Well this is the new AT A900X phone I will just copy paste my impressions of them. I am listening to the EX600 now.

Lookie what I got this morning!
My initial impressions. Very clean high end clarity, I have nothing that sounds as clean as these. I am surprised at the very full balance these phones have. The bass has opened up a bit since I started playing music on them since this morning. At first I was concerned because the bass sounded reserved to me on open box .
It is all smiles so far. I can tell these have some refinements that are working well for the sound. The bass is extended and layered well. It is more of a neutral sound with great extension on both ends. But then again playing heavier bass end tracks. These just threw a huge smile on my face!! Money well spent.! These have not a thing in the sound signature that is lacking or recessed. Everything sound crystal clear to me. Highs, mids, bass all smooth and full with a clean glass like clarity. Much like my WS55 when a track calls for heavier bass, the bass comes out to play. When a track calls for precision and clarity. That is what you get. Oh man these are awesome guys!
Pros, 1) New pleather cushy pads
2) Comfy
3) Looks awesome in all black
4) Clean clear sound, supremely balanced and smooth.
5) Wide stage for closed but you guys would have guessed that already
6) A high end AT sound with Bass! Oh man what can I say... Awesome!
7) As smooth as they sound now I can see these getting better with burn in.
8) Great value for this sound for sure! I wonder just how much more you get sound wise with these compared to their signature high ends..
Cons 1) These will probably sell for cheaper when they release them in the states
2) Needs some serious burn in.
Will check back in about a weeks worth of burn.. I am very impressed. Malveaux. Katun, Santa says these are the ones to get this Christmas. I will give these a hearty Dsnuts thumbs up!! Oh man the bass is opening up! Oh Yay! These are sounding better and better as I listen to them.
I am very impressed with the AT A900X but they better be for the cost. The EX600s are also very impressive.
Now I can see why the EX600s have their fans. These are proper sounding IEMs for sure. Very clean well balanced smooth but. And here is the big but. The monoprice 8320 are very similar in sound. The Sonys highs are bit better extended in the highs and has just a slight edge in clarity. .Going back n forth on sounds. Seriously. .The 8320 give these a run for sounds. They sound VERY similar. More impressions to come.