About dialog animation is often sluggish
In about dialogs, the animation sliding the "Contributors" text view is heavy and often loses frames even on relatively powerful systems, especially on Xorg. While it is indeed a very nice and intuitive animation (though the only occurrence in the whole GNOME environment), it would be better at least to optimize this or "sliding widget animations" as a whole (e.g. by inhibiting redraw until the animation is over)