Have one. Will be returning. Specifically for code (via the Mac Airplay) it's.. okay. The reality is that the resolution / clarity just isn't high enough to rival the sharpness and clarity of a real monitor. So you end up with a bigger screen to try to see things as sharply, or an overall "bigger" ui experience — either way leading to less real-estate per degree-of-view to work with.
So.. it's fine. But it's not better than a monitor.