I'm mot sure which ones are better. I tend to prefer the ones with extra
border but I think it's only because I'm used to seeing them that way.
Some notes about your screenshots:
- In scrensaver there is a slight offset between the window border and the
tabs, the other preflets don't have this in your screenshots. Adding it
will look better (I don't remember how this is done in the code).
- In mouse, you kept the bottom border and made it run on the whole window
width. There is an existing border which doesn't cover the whole width and
probably should. But then, the window looks like a stack of unrelated
items, which is not that good. Maybe there is no need for a border at all
in that case, as there are (currently) no tabs. However, there is sstill
this plan about merging Keyboard, Keymap, Mouse and Touchpad into a single
combined "Input" preferences app, and in that case the border would be
needed again.
