Originally Posted by codiac2600 
Pentax engineers had two choices when updating the K10D in order to stay profitable. One was to advance the AF system and mechanisms to bring it up and beyond the current cameras in the class. Second was to advance the imaging and allow it to be the most advanced photographic tool available. Pentax went with upgrading the imaging guts because having a better AF system and the older imaging end wouldn’t sell well enough. Every camera on the block has a newer AF system, but the imaging system isn’t anything that stellar till you jump to the full frame models.
Well, I am the one who would choose the first option.
Stunning IQ is worth nothing when picture isn't taken because camera was not able to take picture at all in AF-S mode. Or face of my daughter is out of focus because AF-C was not able to keep-up with her.
I am more than happy with K10D image quality. I am much less than happy with it's AF system. I would definitely upgrade to K20D if Pentax would implement class leading AF system in it. Unchanged AF system of K20D is the show stopper for me... I will skip it with hope that K30D will get proper AF system.