For the most part I agree. However, with the number of tabs I have open the close button is usually hidden, and Firefox doesn't show a default icon for websites

For the most part I agree. However, with the number of tabs I have open the close button is usually hidden, and Firefox doesn't show a default icon for websites that don't have a favicon (not sure if this is new or old behavior). I often open up a bunch of text files in tabs from a FTP-like site without a favicon, and sometimes it is hard to tell where one tab ends and the next begins in the new interface.