Why is AV leveling considered good? I'm assuming you're on a server where your side always wins? I would think questing is better?
Server and Battlegroup doesn't matter for normal Battlegrounds. Most of my characters are Alliance which wins 90% of the time (regardless of server) however you will still get more exp as a horde on AV weekend vs non-AV weekend. Questing is good if you can watch it because it can be buggy and if you play on a PvP server (like me) it can be pretty useless where as AV is very reliable and rarely if ever bugs out. I would probably quest bot while around the house if I played on a normal server but for a PvP server I find it much easier to just AV and leave it alone.