This was a longer-planned upgrade to our Subversion server that happened today: moving from the 1.1 series to 1.2.1. It went smoothly, especially because I played it safe by doing a dump / load cycle (more details to be found in Migrating a Repository) with all repositories. Safety wasn't the only concern: as detailed in the release notes, I also wanted to move the repositories to a FSFS back end, and take advantage of xdelta compression. I was mostly after server-side features, I don't see many of our devs use the optional locking...