When I was making this choice (K5 vs. D7000 vs. 7D), I really looked aside from technical stuff.
I figured, none of the companies would make any camera any bad - they have too much to risk. With my - rather limited - photography abilities it would be my fault rather than of a camera, if the photos are bad.
So I looked for other reasons. What drove me to Pentax?
1)
Aesthetics. I just love the way K5 looks (compared to the others mentioned above). Small, sleek, unobtrusive.
2)
Ergonomics. It just lies perfectly in your hand. Learning to use the controls is brisk and operation afterwards is instantly intuitive.
3)
Uniqueness. Pentax has this something special, that neither Canon or Nikon have on offer. It's a niche thing. And since I like to stand out a bit I chose Pentax.
Just do a small test. Take a hike in your favourite park/ city square on a nice weekend day and observe all those people with their cameras dangling around their necks. You will only get a nice smile/ friendly grin from the other Pentax users. To me it is value.
4)
This forum. It stands out clearly compared to mainstream Nikon/ Canon forums. I researched them (and here) before buying my stuff. This place suffers the least from "us vs. all others" syndrome. And has the highest merit/fluff ratio among the fora I viewed. Again - value to me.
Well then, once all rational arguments have passed by, and you've researched all those ISO/ HD vid/ lenses/ blah parameters, consider the irrational stuff. There lies the answer to many a dilemma