I'm hoping this will attenuate after the initial F2P interest, but the lag was abysmal last night. There were times I was trying to loot an archaeology node, and my companion stood there dumbly, and I wasn't allowed to loot it myself because it had queued it for my companion. I eventually dismissed my companion and did it myself! In combat, companions and enemies would run forwards, then backwards, and did a sort of shuffling, ludicrous dance trying to figure out where each one really was rather than where each one of them used to be.
This was on Alderaan, with a population of about 80 users. Not a small number, but it was by no means excessive.