[Jonson PL]

Congratulations on your *Ist D, one of the fascinating cameras in the digital Pentax line-up. It is a typical Pentax, in that it got excellent user feedback, but never really got the market attention that some feel it would deserve. If it would take SD cards like my K10, I would buy it in a heartbeat.
The *Ist D really has most that one would need, and great low light ability with the higher Iso.
You could always later upgrade, when the successor to the K10 comes out; if you want a plus 10 MP body.

BTW, I’ve been pretty fascinated by some of the Oly options. Olympus was the one that inspired Pentax to go more compact back in the day. And they seem fairly innovative. And the Zuiko lenses have great reputation from the film days.
Regarding AWB on Pentax, then indoor with low-light, one has to go for the Tungsten preset instead. (Or do manual WB). The limited series lenses are fun too, you could try the 21 or 70.

You mention : “I still have much to learn about the camera.”
And I would say that the same goes for the K10, and IMO with much good equipment. It takes several months of intense use, to really fully grasp all that the camera is capable of.

This is also why, I primarily go for the reviews of the ones spending hundreds of hours of use, going through the product. Or bringing them on in-field assignments like Michael Reichmann.