Read here:
http://reviews.cnet.com/digital-cameras/pentax-k-50-with/4505-6501_7-35792160.html
Some performance and timing measurements were done and sample photos are posted. In short, whilst the reviewer thinks that the K-50 is feature-rich, the Image Quality of it does fall behind the competition, below are some comments that he writes, for instance:
"Image quality
Overall, the image and video quality disappoint, especially on the default color settings. Following a long Pentax consumer tradition, Custom Image still defaults to Bright, a setting that indiscriminately pumps up color saturation and increases contrast, resulting in serious hue shifts and clipped shadow detail. Switching to the Natural setting or shooting raw helps somewhat. If you're not worried about color accuracy, the occasionally surreal colors might appeal."
"For JPEGs I wouldn't recommend going higher than ISO 800. The K-50's images generally look pretty soft, and that gets worse as the noise reduction really kicks in. It also looks like the camera adds some sharpening at ISO 400, as there's a noticeable jump in sharpness at that point."
"It renders a respectable tonal range, with a reasonable amount of recoverable shadow detail, though like the rest of its class it doesn't retain a lot of highlight detail."
In fact, I felt much the same as the CNet reviewer does, when some of the very first K-50 samples were posted.