While I'm usually not a Fincher-head, I really enjoyed "The Social Network." Part of it was the fact that the dark, sinister Fincher style played really nicely with the taut, dialog heavy, and subtley disturbing Aaron Sorkin script.
TGWTDT, not so much. The two storylines did not play well together and seemed to be from two different movies with two different styles. The Daniel Craig journalism scandal subplot seemed to be tacked on as James Bond-like bookends (ala the ode to Maurice Binder's famous 007 opening credits that have Saul Bass influences) and didn't flow with the mystery surrounding the crazy, rich family.
Even with the twists and turns, I could easily pick out who done it and then it became quite contrived with a few dashes of deus ex machina thrown in to get the protagonist out of his jam.
I never read the books, so I'm not sure how well Stieg Larsson blended these two story elements together or whether he, like Dan Brown, was more hype than substance.
Like Alfred Hitchcock and Tim Burton, Fincher needs a good script to work from since they're all more visual conceptualists than great story tellers (though, Hitchcock did have a flair for the latter as well). Steven Zaillian's for-hire script work is usually hit-n-miss (similiar to David Koepp) and that's probably why Sorkin was brought in for re-writes on "Moneyball." Maybe they needed a better adapter of the novels.
As for the picture quality on the Blu-ray... I wonder if Sony didn't intentionally do a less than absolutely stellar 1080p downconvert from the 4k IP knowing full well that TGWTDT will be one of the first true 4k titles on the new 4k medium coming possibly late next year. A studio would never do something that underhanded to make the next new format look that much better to consumers, now would it?