Touch ID fingerprint sensor placement at the very bottom. This is preventing Apple from the ability to use smaller bezel there, although the top one is comparatively large, too.First off, as you can see in the video, one-handed usage of the new 4.7" handset will be less comfortable than with the iPhone 5s. This can be expected, and is an unpleasant side effect of large phone screens, coupled with the now-obligatory
Decreased overall ergonomics aside, the iPhone 6 might still be fairly comfortable to operate with one hand, thanks to the very thin side bezels, and elongated shape of the handset. As you can see in the direct comparison with the iPhone 5s display panel in the slideshow below, the FaceTime camera has been moved to the left of the earpiece slit, instead of being placed top and center, which might throw off your video chats at first, until you get used to the new position.
Last but not least, the oft-rumored "curved" glass panel seems to express itself in only a slight bend at the edges, which would match the rounded phone sides, if the leaked dummies and prototypes are any indication of the final design.