Comparing Pentax DSLR models

Using the Side By Side option of DP review site I have compared the following models of Pentax - K-30, K-50 and K-500. I can hardly see difference between them. What are the "on paper" differences between them and what are the "real world" differences between them?
Will I see a big difference between the K-30 and the K-50?

The main difference in specification is between the K-500 and the other two. The K-500 is not weather sealed and does not have illuminated autofocus points in the viewfinder. For many, the latter is the more important omission. There may be some subtle tweaks to image processing compared but the K-50 and K-30 are essentially very similar cameras in different bodies. If you can find the K-30 cheap as an end of line deal, that makes it worth snapping up while you can.