I'm looking to buy one of these and can't decide. In everyday usage would the K5IIs be that much sharper. I don't blow up huge prints and i'm not a pixep peeper.
What lenses do you use? What kind of photos do you take?
Finer sensor resolution can visible with even mediocre lenses but it really needs top IQ glass to see a significant difference.
Moire isn't as common a problem as is sometimes suggested but it tends to be more obvious with fabrics, so portraits could be problematic (and too much sharpness can exaggerate skin blemishes).
Stopping down increases the effect of diffraction: by f/16 the chances are that any sensor difference is eroded away. So if you typically stop down (f/8 or smaller) you'll see less difference between the II and IIs than if you shoot at wider apertures.
My take on all this is that unless you have a specific set of needs that prioritise resolution, and supporting lenses to match, the K-5IIs adds as much risk as it does benefit.
First camera 1953, first Pentax 1985, first DSLR 2006