I remember in Cata you could purchase tabards after reaching a certain level of rep with a faction. Then when you did dungeons you got a little xp for each mob killed and little bit more for each boss killed. I really enjoyed doing those as it felt like I was making progress instead of waiting for the world quests to reset. I am a bit late to the Legion party so I am nowhere near all these people with the allied races. I wouldn't even mind if they gave 2 or 3 rep per mob, I just want to feel like I am making progress, not just waiting to do a few quests that give only 75 rep.