Originally posted by mikemike I wonder if someone with experience using K-X, K-5, and K-5ii could compare the AF on a scale from 1-100 to know whether it is worth the price to move from the K-X to a new camera. I believe the K-X, K-R, and K-30 all have very similar AF systems. I was thinking about selling the K-X and spending a few hundred extra to get a used K-5.
This is a whole entire thread and probably should be moved.
I disagree strongly with your conclusion that the AF on the K-x, K-r and K-30 are the same, unless you are talking about AF in decent, natural light. When things get tough, they perform differently. I own a K-x and K20D and returned a K-5 for wonky tungsten light AF. I also read two Pentax boards daily, and here is my ranking of the bodies you are considering, from poor to best AF:
K-r (way to many complaints of misfocus in low and/or tungsten lighting)
K-5 (better but same issues)
K-x (not brilliant but serviceable)
K-30 (better than all the above for artificial light)
K-5 II (best Pentax evah, solves the low and artificial light issues)