I spent last week photographing
Ладога-Трофи Off Road -competition in Russia. Pictures will go to Russian 4x4 -magazine and one Finnish 4x4 -magazine. Taking about 2500 photos in very hard circumstances. I actually once float my camera and brand new 55-300mm in a swamp when I was crossing it. The reason was that I was the wrong side of the swamp to get "good" pictures so I have to "swim" to the other side. And I was more than happy when my K20D works and new zoom was able to work just after filter cleaning.
So K20D is really made for hard places where you need your camera reliability. By the way the new 55-300mm is excellent.