Properly set up, there is nothing that I have auditioned that has been able to convey the subtleties of the musical event as evocatively. Careful setup by an experienced individual is essential. I wouldn't consider them without the assistance of an experienced setup person that you trust.
When all is right they are absolutely scintillating. For example, a recent SACD of Opera Arias by the soprano Anna Netrebko on DG is positively soul stirring. In particular, "Crudele? - Ah no, mio bene!" from Don Giovanni is arrestingly sung with great dramatic fluorish and an upper register to die for. This is a great young singer that I've only heard better at her debut with the San Francisco Opera. All of the qualities of her live performance are on display on this recording, and it sounds thrilling through the WP7s. Others (lots and lots) haven't conveyed either the sweetness or the boldness of her voice as convincingly.