Originally posted by Toro Is not having an aperture ring clearly a disadvantage?
It is for the small percentage of people who might want to use such a lens on a film camera that cannot control the aperture on its own. But considering that no such cameras have been made in decades, that replacing such a film camera with one that can control aperture would cost all of about $20, the fact that none of the cameras made in the last couple of decades can use the aperture ring properly, and few of the DA lenses work well on film anyhow because they aren't designed to cover the full 35mm format, plus the fact that the aperture ring adds complexity to the body design - and I think removing the aperture ring was the obviously right thing to do. In particular, even if the 55-300 had a ring, it still wouldn't work well on your K1000, because it doesn't cover the full 35mm format.
Quote: Are there any other good performance commercial lenses that will work well with both cameras (any recommendation)?
Note that any lens that worked on both would of course work *differently* on both due to the crop factor. But sure, any of the FA lenses (not FA-J, as these also lack the aperture ring. They mostly aren't very well suited for manual focus, but they'd at least work.
BTW, you started two different threads with the same title. I have merged them.