Ah, if the seed is an actual repostiory I may as well just use bzr directly. (It's not as if I'm doing anything other than pulling into it.) I don't think there's any DVCS that will be noticeably easier for general users that any of the others.
I suspect John may be using Windows. My only real experience on windows (using git) is that with their alternate line-ending convention and many windows programs autoconverting, it's easy to end up with with what looks to the version control system like an altered file if you look at a file in an editor which then decides to autosave. That confuses the bejezus out of me, so I hate to think what general people will think.