AH!
This post explains exactly what I mean when I say that I'm impressed but not convinced: http://gigaom.com/2010/01/03/objectified-design/

The design of the device has yet to move past that point of "getting out of the way" and therefore, that friction that the N900/Maemo 5 has causes me to *see* it more than I *see* features on my N97.