Mine arrived from BH this afternoon. I've been shooting with it and the 7D side by side for a few hours and I have to say this K5 is a better camera in every way aside from AF.
The sensor in this thing is amazing.
-Better resolution (more detail)
-Better ISO
-MUCH better shadow detail retention (DR)
-Much less blown highlights (snow here in maine, this thing can get snow detail and shadow detail, the 7D struggles with that)
-It's weather sealed with DA* lenses for half the price of similar L glass.
AF-C is improved over K7 and AF is more decisive. It "feel" very similar in performance to the 7D for locking minus the SDM motor being significantly slower than ring USM. I am very happy with it and don't feel like it's a massive limitation from the 7D.
Pentax also stuffs SO much more into the camera for options that I don't have with Canon at this price range:
-I can set ISO noise reduction per step
-I can set program lines
-I have green button
-Mirror lock up is much easier to deal with.
-remote is cheaper and has IR ports front AND back
-just more in the menus to customize.
Failure absolutely not. Right now this is the best APS-C camera out there. Stains are gone and FF is gone.
I can't autorotate though so better sell all my pentax gear.