I've been kiting these guys solo since 35. They con Blue to red for me. Decent loot but nothing exciting. The snare, but sometimes it takes a few times. The red ones Die easily for a 2 druiud group.
Just a note: I was unable to actually stun these using spells. The spell did damage meaning it was not resisted but the giant was unstunned. This is the only MoB I have ever seen that has done this.