The review team at PC Magazine were particularly impressed with the low digital noise in high ISO pictures. The digital noise was so low that it was comparable to a full-frame camera.
The main downside with the K-3 that all reviewers point out is that it does not have auto-focus during video shooting. To refocus during video shooting the user needs to hit the focus button.
My K-7 and K-5 both took video but I never took any video with either. Ever! And I suspect most serious users of a camera like this are going to be the same. The fact that it takes video is going to be something that they never put into practice; or very rarely even think to use.