I play Ret/hunter in 2v2 at 1900 MMR, all the healer/DPS teams we face are hard, the hardest are definetly priests, you think you have them down, and life swap happens.
I had a game the other day, Resto druid BM hunter, it lasted TWENTY MINUTES! A double dps arena game that lasts 20 mins... BM hunter wasnt bad but it was blade edge arena so I ran away lika mofo all game long. We ended up killing the hunter.
But that said, 2s are not balanced, sadly. I much prefer have 3s balanced than 2s