16-55 seems instant. It was pretty fast before, but now it's like "D4+24-70 instant" if you know what I mean. Face + eye detection works--it's a pretty amazing feature, actually, and seems to work as designed. I'd like quicker initial face acquisition, but I'm not complaining. Haven't tested with multiple people in the frame yet. I have the 14, 23, 35, 56, 54-120 and 16-55, so I'll post some findings later I have another X-T1 coming early next week, so I'll have an old firmware to compare to the new, that should be interesting!