Now that we're back to using GripCrop with the latest script, I've always wondered whether I should be using a Resize of 2 or an Overlap of something else for my encodes... In Moviestacker, you can find these settings under "Blocks TV-Overscan". Thanks!

As a rule of thumb ( or muaddib's rules of thumbs ) I use "resize" for full screen movies, and "overlap" for wide screen movies.
Then for resolutions greater or equal to 528x, I use 2 blocks-TV overscan. Below that, 1 blocks-TV overscan.

-kwag