The 2.8 I have is super sharp and is a beautiful little thing, but hard to use filters with as it will vignette in the corners a little. It's tiny and amazing and makes any body so easy to handle and pack. The faster lens I think is a great piece of kit but even used prices are close to a the newer cv 28mm which is a bit larger. I have a number of fast 28mm lenses, the cv f2, nikkor f2, and olympus f2. The cv 28mmf2 is my favorite of the bunch, and olympus 2nd, 3rd would be this canon 28 2.8.