Hi Arghs,
The PVP win ratio is probably not that much better for Horde on Alterac, although even a non-PVPer like me can manage to get in a winning group after 10 or so runs. Honestly, I'm not sure what the battleground situation is like on the sister guild on Arygos (PVE server) as I haven't tried it, so hopefully one of our PVPers will be able to let you know.