I wanted the K-S2 but missed the Costco sale ($499 with two lenses and a bunch of other stuff) by two days. I got the K-50 with rebate, lens and flash, so net price was $129 for a brand new K-50 body. What's not to like?
The other night I was forced to take some pictures at ISO3200. Lovely. There is some noise, but it is sharp like film grain, not like straw thrown on a floor. It has a beefy grip and a solid feel. It is adept at handling any lens I put on it (I have only one digital, the rest vintage, plus a Rokinon 8mm).
The only shortcoming I can see with the K-50 is no articulated screen. I have one on my FZ1000 and it is almost indispensable.
Other than that, I can honestly say: I love my K-50!
Even though it's just 16mp, the images it puts out are spectacular.