My biggest challenge with this was reading the instructions. As a 67 hunter with a behind-the-curve 62 Sporebat pet, I skim the quest, only process the words "Kill," "tree" and "Sylvanaar" and head off there to kill the first tree I see. How many could there be? It turns out that there are two, and the one I found first was the Level 70 Elite Ancient Protector that guards the place.
The worst part was that I didn't even notice, not while I was busy killing Sylvanaar guards, not while lying in wait for the Protector and hiding from some Ally PCs (since I was now flagged for PVP from killing all the guards), not while getting my face stomped by the tree while thinking to myself, "this seems hard for a level 66 quest," not even while I flew back to the Horde camp to pick up my level-appropriate Gorilla, return to Sylvanaar, kill some more guards and burn down the Ancient. No, I finally noticed when I looked around for the stump and it wasn't there.
Then, I actually read the quest, cursed, flew off to the south and got fried by a Griffon Rider, my body falling amid the tallest peaks of the mountains. Hello resurrection sickness.
After all that? The guy's easy. Clear a couple cats/fey dragons while he's pacing and -- assuming you can read better than I -- you won't have trouble.