Yes works great, i have a strap that holds my iPad to my ear
I can see this only being useful if your phone is in the other room and you're using your iPad. Otherwise you're draining the battery on TWO devices when you could just be draining it on one.
The SMS relay feature, on the other hand, is awesome, because now you can SMS with a real keyboard if you happen to be at your Mac when people text you. Woo!
i just called my dad on the iPad air through iPhone 5, the quality suck right now.
but you have to have bluetooth enabled on both devices . . .