Please reduce margins back to the way it used to be, and consider increasing the width of the menu on desktop.
Also, perhaps the number of notifications shown could be responsive, based on the max amount you can show without causing scrolling? That should be the cut-off point to show “View older notifications”.
I dunno, I like the additional spacing. Looks less like a giant blob of text.
Perhaps something else could be done to make it more compact. Does it need the full thread title, for example, or should it trim to fit on one line? I never find myself needs to read the full title. I either know what it’s referring to or I click on it right away.
I think spacing is mostly ok, could perhaps be tightened a tiny bit. I do think the panels could be a bit wider on desktop @eviltrout particularly the search panel.