There might be something not entirely setup yet. Looking at this I get 11 Mirrors as option, but all of them returned with the same Prio (100)
looking at for example http://download.opensuse.org/distribution/13.1/iso/openSUSE-13.1-Addon-NonOss-BiArch-i586-x86_64.iso.mirrorlist (also based on MirrorBrain) the provided mirrors are clearly differently prioritized.
Might be worthy to have a look at this.