I haven't used the Replay, but I think it would be very difficult to look at two different videos, shot in different lighting and uploaded to youtube no less.... And be able to determine the sharpness differences. I'm a pro still photographer, and I would guess the Replay is probably as sharp. These little cameras interpret the raw data. It could be as simple as the Replay doesn't sharpen the image as much (digitally) in camera, so that the last bit of sharpening can be done in editing which gives the photographer more control. It's said that lighting can have a profound effect on perceived sharpness. I would look for side by side test results before making a discision.

My feeling about the wide lens is this. When you are watching a full HD video that is not panning right and left, up and down, the wide view lets the viewer look around, giving less tunnel vision. The down side is you can get some shots that look pretty goofy. In that case you can crop to 720p in your editor and it's less wide. Just my 2. ... Aaron