I'm running 12.04, and prefer the more conservative style "normal" scrollbars over the overlay scrollbars. I have set them to false in the terminal:
gsettings set org.gnome.desktop.interface ubuntu-overlay-scrollbars false
However after doing so, with some apps (e.g. Nautilus, Document Viewer) my scrollbars only view a vertical bar, but no arrows on the top and bottom to scroll up and down. With some programs these are shown though, for instance Gummi and Texmaker.
It would make a big difference (for instance when having to scroll pdf documents containing several hundreds of pages) to have those arrows reinstated. Is there any way to make this work?
You could try the methods outlined by Webupd8.
My favorite is the uninstallation option:
Bear in mind that Webupd8 says that this may cause dependency issues with metapackages, although in practice I haven't had this issue with 12.04. If you do have dependency issues, I would advise against removing any metapackages and instead recommend that you use one of the other methods.