I'm using gnome-shell and all seems to be good but I've only one problem. Nautilus seems to be very slow only when I use the theme "Faenza", with other theme is all great. In particular Nautilus is slow when switching from one Nautilus window to another the gtk is slow to load and i have to wait about 1-2 seconds before the right colours are shown.
How can I fix it? Has anyone had problems like this? I'm using Ubuntu 12.10, Gnome-Shell 3.6.2 and Nautilus 3.6.3.