I don't have an HP Dev One, but I bought the HP Aero 13 for my S.O. last year as a Christmas gift, and am silently jealous of it anytime I see her using it. It's crazy lightweight (under 1kg!!!) and portable, and the keyboard and display are surprisingly nice. HP have really stepped up their game.
I still can't believe they gave it a nipple mouse without a middle button.
What are a few of the things you like about it? Besides price ($1099, btw)