Griffin AirCurve Dock Amplifies iPhone Without Power

We have seen passive iPod amplifiers/speakers in the past.  And I get the allure of amplifying the tiny iPhone speaker while not wanting to use electricity.  But until I get my sample of the AirCurve from Griffin (Griffin, this is your cue to get a sample in the mail for me ASAP :0) I will remain skeptical of their claim that the sound (is) akin to a set of desktop speakers.  Either way it will only cost you about $20.