While I would love to shoot "
... in near total darkness with decent AF and sharpness" I really cannot justify the price of a K1; especially as I will very soon become a pensioner
That said, other than having to clean up the occasional bit of noise, especially with gig photography, I am extremely happy with my K3. Better still, an unexpected bonus means I have just bought a second, brand new K3 body to go with it. And it cost about 1/3rd the price of a K1 (and was only £20 more expensive than a second-hand K3 from the same company). So no more fiddling around swapping lenses, dropping the lens caps, cursing the dust, MISSING THE SHOT. I am a very, very happy bunny at the moment!!!