I continue to level my horde character in battlegrounds. Sometimes I do pve quests to mix it up, but when bg queue times are low I just jump into whatever I can get into first.
I failed at seeing all of the horde side I could possibly see. I should have leveled up 1 horde and 1 alliance at the very beginning of release. Back then it would have been fun to do pve with other players. Now you see a few people now and then, but I have more "player" interaction in Dragon Age: Origins than I do leveling up in WoW.
So battlegrounds is where I spend most of my time. I'm high enough to mix in Alterac Valley and Eye of the Storm.
For the first time since I starting playing horde, I'm at the point I wish I was max level with the hopes players starting cooperating more. Because last night I heard my first "I'm just here for the xp".
I want to win every bg I enter, even if it makes it last longer. I don't like rolling over and playing dead.
I haven't kept a tally, but it seems horde wins more Arathi Basins than it loses as expected. It wins more Alterac Valleys than I expected it to (when I played Alliance it seemed like we always won). And Warsong Gulch has been a surprise. Alliance side at least at 80, horde seem to always win, but leveling up it goes both ways. Eye of the Storm for the sake of equality being a symmetrical map is proabably the most boring bg of them all. I think horde loses more than it wins, I can't really tell.
Being the underdog I like playing AV. It's one of those bgs horde can win, just by playing smart. Of course there's the rub. Alliance can win by playing dumb. Guess which side wins the most.
I'm looking forward to hitting 80, although I heard the 70-79 bg is sparse. I'm, to my own surprise, am not looking forward to questing Northrend if I have to. So at this point I don't know if I'll ever hit 80 anytime soon.
10 hours ago