Rated 4 out of 5 stars
Great to have the menu bar back on top again. Wish it had the option to have the tool bar below the tabs, but can't have everything I suppose. Still better than the tabs on top.This review is for a previous version of the add-on (220.127.116.11).
What you want is possible without an add-on: create a folder "chrome" in your profile folder and add a file named "userChrome.css" with the following content:
-moz-box-ordinal-group: 10 !important;
-moz-box-ordinal-group: 30 !important;
However, this add-on is required for moving the tool bar, as it is not moveable via userChrome. If you don't want to move your toolbar, you shouldn't need it ;)
If you struggle creating the userChrome, look at this article: http://kb.mozillazine.org/UserChrome.css