I haven't heard any of them yet, but I think I'm going to try the Westone 3s here shortly.
From what I've gathered, the IE8s strengths are in amount of bass (good but not exceptional quality), good soundstage (at the expense of isolation they're partly open), and good midrange. The Westones are somewhat close (to each other, not the IE8), with the 3s being more aggressive with more bass (thats supposed to be very good quality), and you sit back a couple of rows presentation wise. The UM3X are similar but more balanced and smoother and a more upfront presentation with a fairly closed in soundstage.
I can definitely understand, I've been trying to decide what to move to from my Phonaks. I'm going for the 3s because I think a more aggressive sound is what I'm looking for. My guess is that the IE8s would be similar to your ESW9s, so that might help in deciding (do you want that similar sound or something different), although I can't be totally sure on that as I've also saw them compared to the UM3X (I think for the smoothness of sound more than anything).
Head-Fi is practically useless to me now, its all conflicting reports and most people who really trumpet any specific model seem to only have really heard them extensively (in other words they might have briefly heard some of the others but they buy one model and are happy and so laud it). It doesn't help that half the people want to be known for finding the next giant-killer, so every new $100 one gets a cult following and half the people harp that it can hang with the high end ones.