Prior to the nerf, I'd definitely say that this was the go to relic. It gave your pets pretty much any offensive bonus you could think of including flat damage, crit damage, %damage, retaliation damage and total speed. As well as %health regen, DA and vitality resistance! If that sounds like a lot, that's because it is.
However, despite what the link says right now, the crit damage on Ancestor has been reduce to 15%. You see, this build actually gets a lot of pet OA and so a lot of its higher damage was coming from critical hits. The other bonuses are great but 15% means that the crit potential isn't as great as it once was.
Use this for leveling, and change it once you get the next one.