These volumes are invaluable for family history and even more useful for local history.
Back in 1988 Stirling Council Libraries republished Duncan and Jamieson's 1868/9 Directory for the Stirling area. But the new website has this with eleven other examples.
They can be viewed online or downloaded as PDF files and, of course, are fully searchable. This really is the sort of thing that makes the web worthwhile. Here is a list of the heads of household on my road in 1865-6 (when the houses were still being built). Now a list of 12 bakers in the town and area in 1909.
So, even if you are not presently working on a project with some specific questions, it's worth taking a look just for fun!