Let's just say I respecced Doomkin today. I'm 55, and I've been Feral this whole time, and I love it to pieces. I intend on going back to feral at 70, but I thought I'd try laser-chicken.
Anyway, a note on Treants, they're so good that I accidentally ganked a horde druid. The way they attack is very different compared to a hunter or lock pet, even a shadowfiend/water elemental. You don't get a pet bar, so control is minimal, and they seem to attack based on proximity, and perhaps respond to you being hit (I'm not 100% sure but it'd make sense).
So I had treants up to kill a furbolg, and then I walked across the camp to find more, and I ran past a druid who was doing the same quest. 30 sec later my friend says, "lawl that was just mean." and I replied, "What did you kill him?" he said, "No, your treants did."
I had no clue! It was beautiful, couldn't stop laughing XD.
But yeah so far Doomkin is fun. My only complaint is the downtime. Ferals have ZERO downtime, unless you get in a couple jams, then you just heal yourself and innervate and it's game time. I have to drink after every few pulls like I did with my priest, but overall it's still fun. Treants ftw.