Thanks everyone for jumping in.
I shoot in RAW for best results, but the OOC jpegs are just fine, as long as you're careful with exposure. I give the K100 series an edge - I think it has a little better jpeg engine than the *ist series.
The only battery trouble I had was when I used some off-brand rechargeables in the K100D. Random shut downs, and crazy battery gauge readings. I've had no problems using Eneloops, Duracell, Rayovac, or Energizer brand rechargeables. I don't use regular alkalines.
Here's a jpeg from the K100D, taken in 2011. I think I did some minor PP (vibrance/sharpening) on this one. DA18-55 kit lens: