Alternatively, mod it.
No, seriously... I think you should consider the possibility.
I don't think you have heard what the ES10 drivers are capable of until you have gone through hell and back with it. I feel like I'm at a point where I can start to write up on how to modify a stock ES10 to where my ES10 is now.
I thought the ES10 could not be improved any more after what I did a while ago... until I saw how Audio Technica structured the dampening material in the ATH-W1000... and tried to apply the same principle to my ES10.
Compared to the stock ES10 (thanks to Baronkatz for letting me hear the stock ES10 again), the modded ES10 is a very different beast.
I was able to get more midrange, the sound was either as smooth or even smoother than the ESW9 from top to bottom, and bass is far tighter than stock ES10, with more sub bass for an immersive experience. I was really satisfied with my ES10, because it had very good clarity and depth at this point. It's not just me, since a friend of Baronkatz's (hey, Jon!) also confirmed this with me.
We also had an Edition 8 handy... and while I must admit that I liked the soundstage of the Edition 8, and also that it would beat the stock ES10 at pretty much everything (except for bass and the ED8 is very sibilant), I thought it did not measure up to my modded ES10. I think Jon and Baronkatz will have more to say on the matter.
So the ES10 does have room to grow. Even at this point, I don't think I have done everything I could.
I was thinking of selling the ES10 after turning it into an ESW10 and instead just move on to a different Audio Technica headphone. But... thanks to the W1000, I have seen a new limit.