I've read on countless forums about the pathfinding for Ellie and other characters. People complain that they don't like how she can run around and be seen without consequence, but there's already a thread on that (and I think people need to understand how horrible it'd be if Ellie could give your location away).
I'm talking the complaining about how Ellie runs around in front of enemies and even bumps into them. I don't understand how this is happening.
When I play Ellie stays right on my heels. She's always behind me, crouching, and she always takes cover behind stuff, usually it is the same piece of cover I am behind. When I move around, she follows right behind me.
Never in the game have I ever seen Ellie bump into enemies, or even move in front of them. I don't see how some players manage to get Joel and Ellie on two different sides of the room with an enemy between them. Ellie, if her AI is like in my game, should be directly behind you at all times and should never be separated enough to where she's on the other side of the room.
I've never experienced this problem.
Ellie is probably the best companion AI in games I have played so far. She helps me out a lot. She stabs the guys that choke me. She stuns them with bricks/bottles. She points out where the enemies are located. She even points out what kind of gun they have. She says like "Oh sh!t Joel, that guy got a shotgun". And sometimes she stabs them to death. And when I held one of them as a hostage, she makes sure that they won't do anything stupid, if they do, well she shoots them.