On one of my computers Xcode always seems to download... twice. I can't for the life of me figure out whether its doing some sort of "serial update" where if I miss a version in-between, it first downloads and installs that version, then immediately starts the latest one, or if its just a weird bug where it installs the latest version twice, consecutively, for no apparent reason. I've seen other people report this as well. I find it hard to believe its the "serial" explanation, as one of the few benefits of just downloading the entire program every single time is that it shouldn't need the intermediate diffs. So yeah, I have no idea what's going on. My other computer seems to not have this happen... yet?