The Fanedit is somewhat better...but only for a fan.
What I mean to say is that while some of the added scenes raise the "cool factor" of Prometheus,
there is little (perhaps only the worm discovery scene) to illuminate/elaborate on story/complexity.
Likely, NGRO1, there is more/alternate cutting room floor material their holding onto for the inevitable directors cut.
IMHO they should have skipped the foreplay this time, swallowed their pride, and only released a director's cut.
However, I doubt it would add much depth or make up for all the missed opportunities which were aborted in the conceptual art stages.