I've only done 4 of the lvl 19 battlegrounds. But my pug team has won all 4. At lvl 12 after 4 fights I have had around 6 kills, 1 death, and around 80 assists as a cleric. I imagine going back in a few more levels with better gear will be a lot of fun. I can only speak for my own experiences, but clerics seem pretty good.