http://forum.xitek.com/thread-1138503-3-1-1.html
(in Simplified Chinese)
Two cameras were used at almost the same time to shoot almost the same thing. The Pentax lenses used were DA*16-50 and the FA77LE. Canon lens used was only the "cheap" EF24-105L kit zoom.
There are many sets of comparisons. As direct linking is not allowed by the Xitek server, please click on the small sample pictures in the above thread and open into a new tab/window one by one to compare them yourself! Simple EXIF data is provided underneath each picture.
So, after inspecting a few sets. My conclusion is easy, as the difference is obvious. The K-5 is helpless in IQ when it is compared to a Canon FF, even the Pentax glasses used are more expensive! That's also the simple conclusion that can be drawn from my own practical experience, too, which is for quite long now!