I'd say the soundstage is above average.. not huge. It is however, very accurate and has good width and depth.. imaging is excellent. How well the 003 handles practically everything I've thrown at it (jazz, blues, to classical, metal, hip hop, downtempo, DnB, etc.) is one of the main reasons I like this phone so much.
The movers arrived yesterday.. within minutes of them unloading, I ravaged through the box which contained all my headphones & grabbed the DBA & 003.
I've got to revise my previous statement calling the 003's soundstage merely "above average".. It's obviously been away too long cause when I hooked it up to my iPhone 4, it's got a SPECTACULAR soundstage.
Again, it seems dependent on how/well the music was recorded, but what the 003 is capable of when it comes to soundstage is really quite something.. especially taking into account the fact it's incredibly accurate when it comes to imaging. I'm looking forward to watching some movies with the 003.
Also, I've also found the 003 sounds better from the iPhone 4 than the 3GS, unamped. I know they have different DACs (not sure about the hp amp, though).. but I find the Cirrus chip to be cleaner sounding, more analytical, better balanced (I found the 3GS to be a little aggressive, mid-forward, and a little thick).. the iPhone 4 sounds like a really good match with the 003, personally speaking. The Cirrus chip seems to have better separation too..
How good the 003 sounds unamped is something that I don't think it gets enough credit for. In the midst of all the huff when comparing it to cans in it's class and above, the 003's ability to scale up
as well as down is important to users/owners like me and is certainly considered when choosing phones. On that point alone, it throws dirt in the face of the HD600.
Despite the fact the 003 doesn't leave my house & I've always got the ultrasleek Arrow at my disposal at any given moment, I still love listening to cans straight out of my iPhone (my primary DAP). So, if you're a heavy portable DAP user & are considering the 003 amongst other cans, consider how well those other cans scale up as well as down.. I think the choice is very clear.