I'm working on figuring out high-ISO with the K20d, (new camera to me) at least, though I haven't even seen a K-M, never mind worked with one. (And I'm still working in JPEG here, and in camera for the most part at that. )
Mind you, as a film person, I'm not so much trying to 'eliminate noise' as ...just make pleasing images. In monochrome, especially, any noise isn't terribly-offensive. Exposure is, as mentioned, pretty key in terms of noise, anyway: I've worked with a far-less-forgiving sensor in this regard, anyway.
It's a lot better than I expected to have before I managed to get hold of the K20d, anyway, so my impressions are colored a bit, anyway.
In monochrome, I can get some results at high-ISOs that look a lot like I 'pushed the crap out of Tri-X' at least, and that's useful.
In color, under various streetlights, I'm finding the K20 also has useful things, like being able to shift in and out of the evaluative metering with that lever, and actually I do surprisingly-well for someone who considers herself a B&W analog photographer just hitting the Fn menues and throwing the white balance in a vague direction of where I want to be going under odd light. (Must have learned something while I wasn't paying too much attention all these years.

)
Anyway, maybe being handy with RAW renders a lot of this moot, but for the kinds of *places* where you want to be shooting high-ISO, the K20d has a lot of useful stuff in terms of getting the right exposure and stuff that I have found pretty useful. I wouldn't count that out. (Actually, there'd be some room for design improvement in making the metering selector somewhat less recessed, so it's easier to move and check by feel, but it's just great that it's there physically and not hidden away in some menu.)
It's not as astounding as maybe five grand of Nikon would be, but it's at least as useable as the last high-speed colour *film* I shot. Not quite as nice as I can get out of Tmax P3200, but a lot cheaper. That's something.