Under good conditions, it's very quick and takes less than a second. In bad, well, it depends. And yes, I also have 0 success rate if I'm facing the sun. Was quite annoying when I went on a skiing trip :/ However, what surprised me, if you wear a skiing goggles it can still recognize you and even quite fast.
I just upgraded to .71.
Hello seems a bit better, yes. Though you have to know the distance, angle and eye aperture to make it work reliably.
General OS speed seems better as well. However battery life is not good till now.