I have gone probably the slowest possible route doing 2v2 and staying prot with an arms warrior for a partner. Its been fun and we actually went 7-3 one week. If we get groups with 2 melee its pretty much lights out....in 8 weeks of this stuff I've only seen one rogue that could touch me in my full tanking kit.
So yeah, about 8 weeks. I have had the luxury of not being pressed for time. I have the Coldarra shield and we have killed Gruul the past two weeks. I have been able to work on other side projects and not had to track down an elite hit squad to farm up those points ultra fast.
your hat may be nice, but I have the little white tank top that says Legendary right across my boobs. I win. (or more correctly, H wins)