Mix and match. Right now, my warrior's rocking Righteous and has Heroism voided for later use, and the black MoP crafted tanking blues for when I want to give her a more... I guess 'stealthy' look, for when she's on a night raid. My rogue's got the Warden green 'set' and I'm picking at getting her the Cataclysmic Gladiator set off and on. My hunter's bouncing between Cata-WPL quest greens and the Malevolent Gladiator set. My paladin uses Justicar but I'm looking into the red-and-black Judgement recolor. My DK will likely use their starter blues until I can grind the JP for t10. My monk's working on LFR t14 for her transmog set, to go with the transmogged fist weapons using the invisible handwraps you can buy at Peak of Serenity.