Although we built a very simple code manager, it was quite valuable to us. There are certainly cases in the book where I needed to show more code than I had at first realized. Since every version that ever got compiled is archived by the code manager, I was always able to find just the snippet I needed.
Knowing that the code was saved gave us the courage to make changes. We knew that we could get back to any previous state with only a little effort. If we had written the tool to roll back to a given point in time, we probably would have used it a few times. If we had needed it more than a time or two, we certainly would have written it.
In short, our code management tool was almost but not quite sufficient for our needs. Thats a pretty good place to position tools. We dont want to work on them too much, to the exclusion of customer needs, but we want them to be strong enough to serve us. Once the tool reliably saved all versions, it was good enough. Had we needed to roll back more frequently, we had the information to do so.