Since I have it on the brain... Argo is more like The Last of Us. Doesn't break any new ground. The story is... well, history (accentuated). But it does it all very very well, and compellingly.
Cloud Atlas is... I dunno, LA Noire? Trying to do something different... out of the box... possibly not entirely successfully. Sure it's based on a novel. And believe me, I was glad I had read it, though Dr. Pookie seemed to get along fine without a several hundred page cheat sheet.
As with the novel, I still think the separate stories don't really add up to anything much greater, though I think the screenplay actually makes some of the thematic connections in the novel stronger, primarily because of the different way the chronology is interleaved. The film tends to cycle through them all, allowing it to have the thematic and dramatic twists and conclusions of different stories side by side, accentuating their similarities.
I think my favorite section of the sextet in the novel is "An Orison of Sonmi~451", but the film version, though entertaining in exactly the right way to get Hollywood producers' coffers open, is a poor substitute. Then again, it might be hard to accurately film a 22nd century Bildungsroman written in the form of an interrogation.
The film has been criticized for its use of yellowface, but given all the whiteface, brownface, penisface and vaginaface in the film, not to mention the peculiar nature of the story, I can't find too much fault in it. So sue me.
Which is all to say that I think conversation about Argo (last week or ten years from now) will be "Great film!" "Great film!" and no more (and kudos to all). But conversations about Cloud Atlas may be longer and more full of meat.
Even if the whole goddamn thing doesn't mean anything much more than...
Don't be schmucks to each other!