I managed to play with one during a Pentax outing in Singapore. If you have used a recent Pentax DSLR, it's just so familiar. Just plug and play. Handling wise, it sits nicely between the K-r and K-5. Ergonomics is similar to K-r. Although its slightly bigger and heavier in specs, it doesn't feel so in practice,
What I noticed is the improvement of the pop-up flash mechanism, it's much dampened compared to my K-r. My K-r flash pops up like a cheap toy. The top of the prism is also more flat, unlike the bump the K-r has. Why I mentioned this is because the flash like Yongnuo 560 which I use just barely fit onto the hotshoe, it's bottom just a paper thin gap to the top of the prism.
Image quality wise, I'm not able to comment yet. For the looks, it's appearence is much more serious than the fun-looking K-r.