As a longtime warlock, I was shocked when I tried beast master.
For trivial amounts of effort compared to warlock, I was able to pump out comparable if not better amounts of dps.
Its been a while, but if I remember correctly none of the abilities I used had cast timers, so you can move and cast anytime you want. Its like playing a melee dps, except your ranged. You have perfect mobility and an amazing animal tank.
Other than maybe getting bored at doing so much dps for so little effort, its hard to see any downsides to beast master.
- P