Some people don't know what they are talking off, or are interested to do harm to other vendors because they are not so happy with their gear.
There is one real advantage of stabilization in the optics, with long lenses the optical viewfinder is stabilized too, but this could be solved when Tamron, Sigma will deliver their long optics for pentax with stabilization still in (hopefully they will do in the future again).
What about
- Pixelshift. (hasselblad, pentax, olympus.)
- astrotracing,
- rotary stabilisation.
- Sensor shift
Compare Nikon with Pentax both uses the same sensor(type) from sony, and deliver same quality.
For me as an pentaxian, I'll think Pentax do the better job. If there were a need for a change, or a second system (not at the moment) I would take Nikon, none of the others.