Product launches tomorrow, so hardly any comparisons can be made. It seems to be promising - wired connection means higher bandwidth and improved latency. Supposedly can do Retina resolutions at 60hz.
I see now, I should have been reading better - my bad. I also read in this thread that Air Display had some troubles with Yosemite, but I haven't updated on my work machine yet so I hadn't seen these problems.
Streaming over USB seems promising though, I needed to plug in my iPad for the battery.