There were two things which hit me at first with v29.0:
I prefer an arrangement with the address bar at the top (under the menu), a bookmarks toolbar underneath it, and the tabs underneath that, but in v29.0 the tabs moved to the top. Previously it was configurable.
My other must-have is the status bar at the bottom, showing the URL of a link when the mouse is hovered over it. This no longer worked with v29.0.
I've now resolved these issues with the help of the Classic Theme Restorer.