Can't remember just now how much you enjoyed the HD650s. I can tell you that the soundstage of the EX1000s is (from memory) better than the Senns. I never felt the HD650 had a massive SS, and I'm one of those who thinks the IE8's SS capabilities are somewhat exaggerated (same goes for the SM3's SS) - perhaps my hearing is more 2D than 3D? :) Doesn't feel like that outside the world of headphones, though.
Now, I haven't heard the HD598s, and they do sound pretty interesting, I have to say, though I'm not entirely sure 'Id actually enjoy/ prefer that type of 'real' sound. What I do know is that the EX1000s SS is the best I've heard. It's still 'in your head' as far as I'm concerned, but it has a coherence about it that seems to be more expansive. No other phone listed in my sig/ profile has given me this level of 'SS coherence', not even my ES3X. There's nothing artificial about it. The word that comes to mind is 'organic', but not sure that makes much sense.
650's don't belong anywhere in this conversation. Other than solid FR balance and refined detail retrieval they do nothing spectacularly well or commit tragic errors. Properly amped of course. Not my cup of tea either at least if I have to lay down my own money.
Agreed on the SM3's, big turn off for me as I'm sure you know. Nothing about the EX1000 sounded unnatural to me except for the treble spike I couldn't get rid of at the time. The 598 SS is not unnatural either. Like I said, I don't like wide SS because it usually always sounds weird and unnatural, gimmicky even. 598 isn't like that, which is why I was impressed and many others are too if you check the thread. Probably their greatest strength. One of if not the best I've heard for orchestral symphonic pieces. I know exactly what you mean by organic and natural, two words I probably wear out more than any others. Haven't heard the ES3X but I thought the W4 SS was a bit too artificial and unnatural to my ears. Didn't like it for my tastes. ES5 doesn't have that issue. It's not congested or absurdly expansive but just natural, coherent, Goldilocks SS and insane imaging. I'm all about natural, coherent sound over tricks and gimmicks. The 598 is the first I've heard to do wide 'right' better than a kicker for the Buffalo Bills.
Edited by Anaxilus - 5/14/11 at 8:54pm