Hmm, well even the best IEM's (and I've heard the UE10 and E500) don't do it for me as well as closed headphones do, as far as sound quality goes. I would only use IEM's where the isolation and/or portability are needed, even if I had the E500's (based on what I heard from them). Now I find Etys sound embarassingly bad, considering their price, and would frankly prefer to listen to HD201's, let alone the A900's. The Etys are the headphones, perhaps more than any other, for which I cannot understand how anybody likes them; between tons of sibilance, absolutely no soundstage, K501-like levels of bass, and no particularly good quality I can think of (other than isolation). I can see how folks like almost any other decent headphone, but the Etys just absolutely puzzle me.