If your Firefox bookmark menu's are a bit tiny on your SP, you can make them larger under "Display" by setting "Message Boxes" to a larger font. I know, it's not intuitive that bookmark menus would be under "Message Boxes" but for Firefox they are. This works especially well with "All-in-One Sidebar", a very popular bookmarks addon. This is nice in case you have been hesitant to go with a 125 zoom because your bookmarks were too small. After you set them it takes a little while for the screen to refresh but be patient, it will.