Originally posted by Motikant landscape, portraits , astro and a bit of macro. Probably not much action
I'd lean towards the K-5iis from that list because of the astro requirement.
K-5iis vs K-5: The K-5 has an anti-aliasing (AA) filter in front of the sensor. It introduces a tiny bit of blur to remove moire patterns that can occur when photographing fine patterns such as fabrics. The iis removes the AAA filter for better sharpness, and the expense of increased risk for moire. Landscape and astro never show moire. Moire is an occasional risk for macro, though.
K-5iis vs K-3: The K-3 adds faster burst speed and 24 megapixels. Low-light arguably suffers. The K-5iis is IMO better for astro. For landscapes, though, the K-3 extra pixels can be useful but only if you need to print very large or do heavy cropping.
Can you find a used K-70 at a good price? That's a newer camera with good low light performance, no AA filter, improved autofocus, and 24mp. That would be even better than the K-5iis for landscapes, astrophotography, and macro.