I've had my D5100 for just over 1 year. Very happy with this camera, and it suits me well for my experience level. For whatever reason, I always used the live view to frame my shots. It was just something that I had gotten used to. I recently started using the eyepiece, and noticed something right away. The auto focus seems much faster when not using live view. The kit 18-55 and the 55-200 seem to take up to 1 second, and the 35mm maybe a bit faster. Going through the eyepiece, It's only about half that, and the 35mm autofocus seems to be nearly instant. Anyone else experience this?