Pretty terrible results here as well. Even when it's working well, it takes about as long as a 4-digit PIN. But it frequently doesn't work well. I have to move the device all around, forward and back and tilt it in different directions before it finally detects anything. Now, I'm sure part of it is that I wear glasses, and I've noticed that while doing the 'improve recognition' that reflections / glare from external light messes with the process a ton. Still, even when I have my glasses off it has trouble a great deal of the time.
To any outside viewer watching me fumble with my phone, it makes Windows Hello look like a joke. Now, I've tried Windows Hello with the Kinect 2 and facial recognition on the PC, and that one is instant. But is the general public supposed to discern between the two technologies? How is Microsoft supposed to sell the public on facial recognition for PCs and laptops if they see people messing with their phones constantly to get iris scanning to work? (I guess part of it is that there aren't enough of us using 950/950XL to matter, but still).
Iris scanning just isn't ready for primetime. A fingerprint scanner would have been far better, in my opinion. I mean, I've got a Note 5 and the 950XL that I'm trying out both at the same time. The fingerprint scanner works the first try the large majority of the time, but even when it doesn't, I can get 4 or 5 attempts in before the 950XL recognizes my iris even in perfect conditions. I hope software can fix it, but I have no idea if the problem is all software or a combination of software and hardware.