I have known Al for a long time...when he speaks, I listen, and I know him to be a great Pentax shooter, and an honest man. Take a look for yourself, this is not an inexperienced beginner.
Flickr: AReidJr's Photostream
Likewise, I know a few others that have no FF problems, and I also find them to be honest and well qualified to state their findings.
Flickr: jthommo101's Photostream
So why is it we are at war with each other here? We are all in that same ship, and should all pull together to get this resolved, and if we are not heard as a group, it will not be addressed, everyone knows that the "squeaking wheel gets the grease".
I find it interesting that Pop Photo,in their D7000 review listed poor focus in low light as a minus and I suspect that the K5 will receive the same unless this is resolved. To have a low light capable camera, that won't focus in low light is not acceptable, whether it is a K5 or a D7000. You can bet that Nikon is hearing about this too. They also reported the Canon D60 was better at low light shooting and did not have focus issues. I am not plugging Canon...I had rather have a MF Pentax than a fully functional Canon......but they apparently did get it right, I can't deny.
Finally, no, I do not own a K5, but instead of gloating that some complainers don't even have the K5, you might consider why they don't. There are scores of us that do not want to go through 2-5 returns or send a new $1500 camera to Pentax for repairs that might take weeks. No one buys a new camera with the anticipation that they have to send it back to the factory for the Mfg to "finish building it". You can call us what you want, but we won't be boxing up and sending cameras back and forth, will we?
Best Regards