Years ago, right after getting my K5 - I just (gently) tossed everything in the pickup and headed off to the Grand Canyon, getting there right before sunset. I shot something like 80 frames (bracketed) with the K5 and it died (shutter motor Pentax told me on the warranty repair). However, fortunately I had brought my K100D and Q along with a new pack of AA batteries. I switched over to the K100D for the rest of the evening.
The next day - I was post processing the take, the K5 images were really nice, great resolution and everything. When I got to the K100D images my heart somewhat sank a bit as they actually looked a tad bit better and nicer. Different lighting, different scenes - but overall the CCD images just had that un-explainable positive difference about them.
I still have the K100D and my K5 - actually, I probably need to shoot with them a bit more - come to think of it....