K-5: http://pentax.briefing-paper.com/1121 (in Japanese)
K-5IIs: http://pentax.briefing-paper.com/1864 (in Japanese)
In particular, the following is the side-by-side f/5.6 pair of the comparison shots:-


(Above: Left: K-5 100% Crop at f/5.6; Right: K-5IIs 100% Crop at f/5.6; Normal Sharpness; Lens Used: FA 31mm F1.8 Limited - Click to Enlarge.)
Btw, with the removal of the integral AA+IR filter of the original K-5, the K-5IIs seems to produce colder picture than the K-5, with a purple tint and tendency.
In fact, the amounts of details of the two cameras are close enough, whilst the K-5IIs pics look a bit "sharper" and "harder" on edges. The fortunate thing is that the focusing accuracy of both cameras is good enough. The K-5 pictures are yet a bit brighter, though, despite that a +1EV exposure compensation was applied for both cameras. Last but not least, the micro-contrast of the K-5 shots seems to be somehow better.
Jaz Johal · 646 weeks ago
Barbarosa · 646 weeks ago
jaad75 · 646 weeks ago
anonimity is great · 646 weeks ago
Z Polski · 646 weeks ago
Barbarosa · 646 weeks ago
joejoe · 646 weeks ago
seems significant