OP made a thread asking about gr with a picture of a gr, unsurprisingly gr users address the concerns and gives their thoughts.
Why are you so upset that people use a different camera?
Stop obsessing over gear and go take photos.>>3606687
Most people have had gr ii's for years without getting dust, its mainly just a factor of fixed lens cameras inevitably getting dust on the sensor if they are used/stored in dusty/linty areas constantly, so put it in a case or bag before putting it in your pocket if you are concerned about dust.
gr iii has the dust shake thing but I don't think it has been out long enough for any conclusions on whether it is effective or not, although one of the major ingress points for dust on the previous gr's were the pop up flash which is missing on the gr iii so one would assume its less likely to get dust on the sensor.