My partner bought a desire. I'm glad I didn't.

Compared to my N900:

No keyboard = absolute HELL.
What good is having fantastic emulated games without flipping buttons?

Sound quality!! OH MY GOD.
Desire sound out of the speakers is absolutely terrible and the output from the audio jack is absolutely sub-par as well.
I am a bit of an audiophile and I regularly play music from my N900 through decent systems and love it, the desire is lacking serious quality in lows + mids and highs are not that great either.

The market store is amazing on desire but that is about it.