I think the con would be, in most normal situations, You're going to have to chose 1 buff, Which forces you to keep out 1 Avatar, Which limits your BP Options, and You have to "Charge" The buff, And your Pet can be killed, meaning your buff goes away and you have to start from square one...I mean, Avatar's Favor needs to have a con, otherwise we would all keep it up 100% of the time, right?
There's already plenty of horrific restrictions on Avatar's favor, The NErf to pet damage was uneeded :|