I play 4xHunter + 1xDruid. They are level 69 now, close to 70. I have been running all of BC instances till Sethekk without problems. More precisely, I used to run with 4 cats for full DPS, and I got miserably stuck in the Crypt because of the many adds that spawn during fights. I then moved to 4 gorillas, and could clear the same instance at the same level without any issues. Next in line are the Labyrinth and the Black Morass.