I'd say BitTorrent is likely just as efficient or much more so at keeping distances short. At least, it optimizes by taking the fastest available peers. Your typical big torrent file could have thousands of peers. That's more endpoints than most any other big CDN and more likely to have a few peers really close to you. Heck, it could even download from someone on your local network if they happened to be serving up the file you are looking for.
