I upgraded from 4.4.2 to Hopper a week or two ago.  I found that while the transition _appeared_ to have migrated my settings, xfce seemed to behave as if those settings had remained at their defaults.  Consequently, I had to re-set all of the settings to what they appeared to already be set at to make them actually take effect.

For instance, in my 4.4.2 config, I had Snap-to-windows enabled.  After the upgrading, the Snap-to-windows checkbox was checked, but windows still did not snap to each other.  After I unchecked and re-checked the checkbox, windows did begin snapping to each other.  This was the case for a number of normal settings, in addition to many (which probably means "all changed-from-default") of my keyboard shortcuts.