Perhaps, I don't know what I am missing with the K3. I do really like the K5's 16mp sensor. I like the ISO 80, the dynamic range along with its image quality. I probably am missing some or a lot of additional resolution that I am leaving on the table. I have one image, that I printed at 20" x 30" that is hanging up in the office and folks comment on the details of the surface of the cobble stones on the pier in the foreground. Maybe, its the one in a thousand images that would not benefit from any additional resolution. I don't know.
I do like a lot of the features of the K3, along with the AA being removed from the K5IIs. I do wish that Pentax would have taken all the additional features (better AF, enhanced WB sensor, image processing, etc.) and coupled them with the 16MP sensor making the K5III or K5IIsx or what ever. I would have preferred that to the K-s1. Oh yea, on that note - I like the K5's body style and layout.