Which healer: Rdruid or Prevoker?

Can anyone lay out the pros and cons of playing each of these classes and which would you recommend for first time healing in arena? I'm looking to play mainly SS but might switch to LFG 3v3 down the line if SS get's too frustrating.

I'm a returning player - I've played mostly DPS pvp in the past and now looking to go healer. Last time I've pushed arena rating (2k) was WOTLK so pretty much starting from newbie level now. I don't mind a bit of a learning curve but I don't have much time to play, so also don't want to choose the most complicated class/spec out there.