Quite some time ago I worked on a couple interesting projects, q2java which embedded Java into a Quake2 server and then allowed for games to be written in Java; and qwpython, which wrapped up the QuakeWorld dedicated server engine as a Python module and came with a QuakeC -> Python translator, so existing QW games like CTF could be converted to Python and hacked on from there.
Some time back I had created Subversion repositories of the various releases of those packages (didn't really know or use VCSes back then), and had them on an Apache mod_svn server. Well, SVN is kind of a PITA, and I'd like to not have to keep that server config going, so I looked at converting those repos to something else.
First tried hgsvn, which has worked pretty decently for smaller or simpler repos, but something in the q2java one make it crap out.
Next tried the hg convert extension, which worked better, but only when using a local SVN URL (like file://...), and then didn't manage to pick up the tags correctly.
Decided to give Git a try, first with Converting a Subversion repository to Git (in seven steps). It worked, but was kind of a nasty process for a Git newbie to wade through. The tags still didn't seem quite right.
Finally, realized GitHub has its own Subversion import built right into the website, and gave that a try. Very very nice, made importing the svn repo a breeze, and seems to have gotten the tags just right. Only took two steps: enter the svn URL, fill in a translation table of svn userids to git authors. I'd recommend this highly for anyone looking to move off svn. See the q2java and qwpython results here.