Auto focus on the HTC One is pretty zippy 90% of the time, but it can slow down when hunting for a focal point in low light (which happens to almost every other camera so it's not a real issue). There is also a quirky blur to some of the pictures, especially when taking the picture immediately after tapping on a focal point. I've found that by waiting a second or so between focusing and clicking the shutter, the image tends to sharpen considerably.
