Here's a few quick samples.
Sigma 10-20 f3.5 @10mm,1/60s, f8, ISO100
...and cropped to upper left corner.
At 20mm. 1/80s, f8, ISO100.
...and cropped as above,
Finally, Sigma 17-70 f2.8-4.5 DC @ 1/80s, f8, ISO100
...and cropped,
All taken with the K5II on a tripod, shooting into the sun(!) and all are jpegs straight from the camera (ie. no sharpening).
I've specifically shown the corner crops as I believe they would show the 'worst' part of the image, sharpness wise. Anyway, it's early days as I've only got the 10-20 this week, but I reckon it's pretty good.
Regards