I know what you mean about cost in relation to quality. I Understand your point, but, to me, if I had to pay for the Sig what I had paid for the Ed9 (which I adore), then the quality has to be the same. I tried the newly enhanced 25 (black and blue) and wasn't really really impressed. My obsession is to get THAT Ed9 SQ in a super convenient portable pair of cans I'm obsessed by Ed9. At home, I'm using them with my newly acquired Z1070 (with PowerAMP software) and the sound is like heaven to me ears. Cheers
Sounds like you might be quite happy with the SigPro's then, I haven't tried the ED9 myself (I've never even seen them in New Zealand!) but from the reading I did before purchasing the SP plus my own take on the signature of these cans I would say they are the best sounding closed headphones I've heard, by a long-shot.
Put it this way, I am happy I replaced my GS1000's with them, The GS1000's are a love/hate can, but those who love them /really/ love them, I really liked them so for me to go in a completely different direction and /really/ enjoy these I guess that's got to be a good thing!
I say go for it, maybe grab some cheaper s/h ones and if you don't like them enough flick them on? Money isn't so much of an issue for me so I didn't mind grabbing them new.