[frey71]

I want upgrade my K-R. I think it's better to choose KS1 or KS2. The difference in the price is 200USD - on Amazon now KS1 300USD, KS2 500 USD. Is there a reason to overpay? Or add another 100USD and take the K-70 from 600? I have kit 18-55, 55-200, 1,8*55.

[Na Horuk]

Here, I think this might help you:
Pentax K-S1 vs. Pentax K-S2 vs. Pentax K-70 - Pentax Camera Comparison - PentaxForums.com
You can also add K-r and compare that camera.

I have K-r and I think K-S1 is pretty good. It is newer, has a lot of features. K-S1 is not WR, but K-S2 is. This can be important to some people (if you have WR lenses and will take photos in bad weather conditions).
K-S1 is really small and capable. If K-S1 is better than K-r, so it is a decent upgrade. But check the features in that link to see if there is anything special that catches your eye

I think it would probably be good option to get K-S1 and buy some more good lenses! This will make big difference! K-S1 with DA 35mm f2.4 or DA 70mm, DA 40mm XS, or DA 20-40mm limited, DA 18-135mm, or even Tamron 17-50mm f2.8.. these combinations will you get much better image quality than K-r with DA 18-55mm.

[frey71]

Thank you for your advice.
If do not take into account the WR, the flip screen, the presence of a second wheel, get a difference between the cameras there? My interest first - quality if pucture.
On lenses and so it is clear that my set requires replenishment. For example DA 18-135mm, or even Tamron 17-50mm.

[Na Horuk]

My interest first - quality if pucture.

I think K-S1 and K-S2 have same sensor. Same image quality. Noticeable difference from K-r, great for prints.
K-70 might be a little better, and KP a little better. K-1 best.

[Clothears]

I think K-S1 and K-S2 have same sensor. Same image quality. Noticeable difference from K-r, great for prints.
K-70 might be a little better, and KP a little better. K-1 best.

Correct. It gives great images. Personally I have no need for a flippy screen (I don't use live view) or a second wheel so the K-S1 was the right choice for me.