Purchased this for the wife for Christmas after her disappointment with her older Samsung.
To date, we've been very impressed. From the box in auto, pictures inside and out have been clear, crisp and well balanced for colour. Chromatic aberration has been minimal, and the same for vignetting and pincushion effects at either end of the zoom.
Battery life has proven to be good (200+ shots per charge, including quite a few flash shots), and the camera is comfortable to use, with a simple and easily navigated operating system.
Naturally image resolution can't be compared with a DSLR - sensor size will always win out, even if the lenses are comparable, but if you're looking for a compact and easy to use point and shoot which delivers quality pictures in a variety of situations, the Pentax Optio S1 is more than worth a look - a cracking little camera at a budget price!