Heyaz says he can take drek by himself with a few lowbies and 1 tower up - post is here. He says he uses just his rocks and his shamans do 5-6k dps on him.

I read another post here recently of 2 5-boxers taking Drek by themselves with 1 tower up. Just hit 80 on my shamans, and Drek basically 1-shot's my rocks x5. My spellpower is about 1300 buffed so maybe rocks have a lot better survivability with 3000 sp - i dunno.