This was a great example for me to customize my own sidebar, thanks. But do you find your row spacing jumps around a little bit?
If there are enough entries to show the vertical scrollbar, then if its scrolled to the top, I have wide row spacing like you show in your screen shot.
If I scroll down some then mouse over the text, the row spacing shrinks.
If I scroll to the top, it widens again.
I'll try comparing the settings with the defaults, but was wondering if you saw this too.