Originally posted by mattb123 One final consideration is if you like being able to use AA batteries. If that is important to you, the K-S1 might be more your style.
Originally posted by Andraya I hate the AA batteries in my current camera, they don't last at all. It's my main reason for wanting to upgrade actually.
Originally posted by mattb123 So don't get a K-S1! I did find Eneloop rechargables worked great in my K-x if you need better batteries in the mean time.
Coming into the conversation late, and the point is moot if you don't like AAs, but since the Internet is forever and others may be reading: the K-S1 doesn't use AA batteries. It uses the same D-Li109 battery as the K-S2. The K-x was the last Pentax body to only use AAs; the K-r/30/50/500 used the D-Li109 or AAs with an adapter clip, and higher-end bodies with a grip.
My K-S1 comes closer to my K-x in small size and handiness than anything else I've tried, but the odd grip and looks put off a lot of people. The K-S2 is a better value, having more features in a package almost as small as the K-x, but a little heavier (if size is a concern).
I will say that the 20MP sensor in the K-S1/S2 comes closer to the "look" of the 12MP in my K-x than the 16MP or 24MP sensors. In my opinion, in low light, the 16MP sensor in the K-5 (and others) has the edge over the earlier 24MP (K-3,K-3II) or the 20MP, but the newest versions of the 24MP in the K-70 and KP are hard to beat.