At work, I have been using the Vsonic RE0 and the Klipsch S4i. Both different, but good IEM's. Through the use of various IEMs and headphones throughout the years, I have learned what I like and dislike. Sibilance is something I dislike, and I do like punchy bass with a more mid-centric sound. The RE0, although a nice IEM, was a little too cold for my tastes. And the S4i was just too fatiguing sometimes.
Based on this review, and the review on Innerfidelity, I decided to give the SE215 a try, and I'm really glad I did. The sound is very good, with good details and separation. The bass is very good, much better then I expected. The treble is still a little too much for my tastes, but I can EQ that down a bit on the iPhone. And the fit of these on my ears are perfect, very comfortable. The best fit IEM I've had (I've had various sub $100 Sony, Sennheiser, Vsonic, Klipsch). Isolation is also excellent. However, sometimes I do prefer the more laid back nature of the B&W P5 I have. But wearing the P5, I feel kinda silly, and IEMs are far less conspicuous.
Thanks for the review ClieOS. Keep up the good work. Now I'm wondering if I should upgrade to the SE535 and if it is a big difference in sound quality.