I think it really comes down to preference. Both work well and for different reasons and styles. Including tech notes and docs into the VCS could be nice, if you use it, but like most project management, it comes down to how you work-- that's one reason why there isn't a one-size-fits-all project management product that is infintely better than any other offering. There are plenty of times I wished I had something like the embedded tech notes to explain design decisions. I use git myself currently, but I've wanted to dip my toes into fossil for awhile to see if it matched my workflow. I think storing the whole repo in an SQLite database was brilliant-- self contained and you don't have a problem slicing the data to get things like all parent commits or descendant commits.