Which is better suited for transferring large files with frequent updates over limited bandwidth? I Haven't been able to find any comparisons out there.
UPDATE
To not preclude other solutions, is something better suited to sending deltas to large files? (Have tried Unison)
Can't give you concrete numbers right now, but I use SVN and git and the last one is way faster.
More propaganda: http://whygitisbetterthanx.com/#git-is-fast
Git can use four major network protocols to transfer data: Local, Secure Shell (SSH), Git, and HTTP.
...
The Git protocol is the fastest transfer protocol available. If you’re serving a lot of traffic for a public project or serving a very large project that doesn’t require user authentication for read access, it’s likely that you’ll want to set up a Git daemon to serve your project.
From http://progit.org/book/ch4-1.html
And an informal memo describing the protocol: http://git-scm.com/gitserver.txt
With large and oft-changed binary files, both git and svn should be basically the same for push/commit and pull/update operations. With large files, you're limited by the size of the diff you're sending. Both git and svn will do compression, so nobody obviously wins here unless one of them works better with your file type.
However, there is one critical point: Cloning a git repository of this sort will be slow. This is because clone will have to pull down all of those diffs, instead of only the latest snapshot.
So if you can avoid the clone command, specifically, you're free to go with whatever tool has the best support for you.
(I will also suggest Dropbox as a good candidate for this task.)
Unison or rsync are probably your best bet. Storing lots of large binary files in a source code control system can cause headaches.