I don't think its a bum unit since I have a solid moca connection for any 2 of the 3 connected (or if it is, I can't figure out a way to tell which one without buying a fourth, hopefully good, unit). Its just the presence of the third device that causes the flakiness
I have a friend that has a ECB2200 that he isn't using, maybe I'll try swap that in and see what happens.