Originally posted by kamisu I should also add that may be instead of sharpness, I should say focused, since in most of K5 (also D7000 or T2i) "macro" photos, on my screen, it looks like all the image is in "boke", while I see more focused-sharp-crisp regions in K10D samples.
Macro shots always have a very narrow depth of field, so anything but the subject (and sometimes part of the subject) is going to be out of focus. A K10 isn't going to change that at all, it will produce the same results. It comes down to the lens used, the aperture used, the magnification obtained.
Really, to address all your concerns, your opinion is being influenced by the glass used for the samples you look at, the exposure settings used, and the resolution of the final image. Looking at 1:1 crops (or full sized images) taken with a kit lens, you're not going to get tack sharp results, but scaled down to a usable size, or printed, they look entirely different. The benefit of a more modern body with a higher resolution sensor is you have a lot more leeway to crop and resize.
As far as sharpness itself goes, it's ALL in the glass. Any DSLR of any brand is capable of producing very sharp images, provided there's a decent piece of glass focusing the light. There is no advantage to selecting an aging camera body over a K-r or K-5, but there's a big advantage to be had putting a good lens on it instead of the kit zoom. There is also a great advantage to be had by taking care in your post processing, applying sharpening in post, rather than the quick and dirty (by comparison, remember it has to be fast and not processor intensive) methods used in-camera.