So far the companions have been less than stellar, I use them mainly as Pack mules. They run of and fight seperate battles leaving you wondering where they went. But my major issues with companions are;

They practically share the same space as you, blocking view with their weapon floating in your face.

If you try to backtrack from a mine or exploding vehicle, they are right behind you blocking your path and boom, dead, or severely crippled.

Dogmeat has pushed me off bridges because I stop and he doesn't.

Dogmeat opens EVERY DOOR causing unwanted Agro.

Companions push me out of hiding into the line of fire because they insist on sharing your space.

Bethesda please put in distance commands like in the previous Fallouts, having to command them every time to keep their distance is quite the annoyance.

Well, you can command the dog to wait for instance, and open the door yourself. That what i do actually.

True, but thats part of the issue of having to consistently remember to command the companion to do something that shouldn't be an issue in the first place. While opening doors is annoying, Dogmeats ability to knock a foe down and hold him is helpful, so making him stay all the time makes that ability useless despite me mainly using companions to help carry gear, I'd like to use them all the time like you could in in 3 & Vegas.