I've tried rsyncing a 3gb movie from my arch box to my friend's ubuntu box, both on the same network (and router). It went really slow, between 50kb/s to 300kb/s and he decided to download it from the internets, instead. That went really fast, 4mb/s to 8mb/s. When I tried downloading it too, I got the same speeds and it really confused me.
Shouldn't rsync between two boxes on the same local network (and router) be faster than hauling it down from the far away internets?