So I checked my slaves win ratio and they are currently at 82wins and 50 losses. So 60% win ratio, I'm sure you can figure out some xp rates with an average win taking 30mins and a loss being around 50mins (horde rarely races on my server, so win by attrition). With that in mind I found the best times to play as alliance on Kil'jaeden is early morning (I would say 90% win rate) and very late night (midnight on). After about 1-2pm Horde starts dominating. These arena geared guys show up and they dont go kill Vann, nope they farm you for 50mins and wont let you do ANYTHING. It sucks because you really cant do anything to them with their pocket healer following.