I bought UM2's recently and very happy with them. They are bass-rich, mellow, and offer detail in mids and highs that are prominent without being "in your face". They are incredibly comfortable too, especially for an over-the-ear IEM.
There is a new model pending release called the Westone 3 that will, allegedly, be the kickoff to a new series that will have a sonic signature closer to the Shures; that is, less bass rich, more prominent detail in mids and highs. I might buy that one as well. Anyway, this could mean that some UM2's will show up for sale used.
Check it out at www.earphonesolutions.com. Great customer service, very knowlegeable. If you order on the web, some of the items respond to discount codes save35, save30, save10 or save5. Mostly they respond to the latter two codes, but every little bit of savings helps. The shure E series has steeper discounts as the new Shure SE series seems to offer more value at each price point.
The best used board I've found so far for used earphones, by the way, is in the forums at www.head-fi.com.
Interesting discussions in those forums, as well as at www.ilounge.com.