I don't have any personal experience of the E-520, but I know several people who have, and they are very happy with them.

I don't think there is a particualr problem with sharpness, and you can certainly sharpen images in camera (if using Jpeg), or in software is using RAW output.

The E520 is also smalla nd light in weight. However, if you are seriosly into wide angle photography, you might find that a bigger sensor (i.e. Canon or Nikon APS or full frame) makes more sense.

The Four Thirds system certainly has advantages for telephoto photography (as focal length is effectively doubled), but equally, ultra wide angle lenses become somewhat bulkier and more expensive.

HTH