Although a direct comparison from any one point in time in either's men's careers is always provisional, due to their ever-evolving theories of the Unconscious, it was nevertheless grounding to read again an early lecture by Freud on psycho-analysis today (from "Five Lectures on Psycho-analysis", 1909). He reviews the early development of his theories, starting with Joseph Breuer's hypnosis experiments.
It is here that we encounter a more sensuous, energetic version of the Unconscious with an obvious intuitive appeal:
... in one and the same individual there can be several mental groupings, which can remain more or less independent of one another, which can 'know nothing' of one another, and which can alternate with one another in their hold upon the consciousness [..] If, where a splitting of the personality such as this has occurred, consciousness remains attached regularly to one of the two states, we call it the conscious mental state and the other, which is detached from it, the unconscious one. (p. 43)
It is as if there are two rivers, both active, but at any one point the one is subterranean and the other in plain sight. Yet both influence each other, due to their connected volumes and velocity.
If we try to find a metaphor that is closer to Lacan's concept of signifying chains we must perhaps compromise on something like electricity, the movement of electrons, and the logic gates of electronics.
Yet another interesting, but as yet unexplored metaphor, might be that of linked quantum states.
I'll leave that one for another day.