When I had my K10D I shot 50% RAW and jpg and I used the default settings for jpg. Now that I am back to my DS, I shoot 90% jpg and still used the default settings, using CS2 for any PP I feel needs to be done.
I find that RAW didn't really get me much more sharpness if any and it was only usefull to me to modify exposure issues, which the K10D seemed to have quite often. The DS on the other hand seems to be dead on with exposure using jpg, so I rarely use RAW with that camera.
That said, I don't have any APS format lenses other than the kit lens and only use FA*, FA, and A* lenses, which the K10D didn't seem to like as much as the DS does.