It's not state monopoly capitalism because the state doesn't have a monopoly on all of the MoP, but yeah, I think monopoly capitalism is more efficient. I remember reading somewhere that monopoly capitalism is actually more competitive than early industrial capitalism was, and as capitalism develops it requires more and more capital to revolutionize the MoP, meaning that only the state and monopolies can do it, like how the state shouldered the burden of funding the creation of computers. That's one of those cases of free competition being a fetter on production, free market capitalism would be technologically stagnant. As pointed out above monopoly capitalism is a necessary stage in the development of capitalism.