Regarding J. EDGAR:
Although I liked it more than BK, it certainly is not one of Eastwood's better films of recent years.
As I said a couple of days ago, I think the story would have worked better as a 8+ hour mini-series, rather than as a 2+ hour movie. I felt the same way about Lawrence Kasdan's WYATT EARP a few years back.
Regarding BK's CITIZEN KANE comparison: Yes, there was a slight surprising story twist at the end of J. EDGAR, but unlike with Welles classic, it didn't really help.
In KANE, the "Rosebud" mystery is set up from the start...and it drives the narrative. Had Eastwood's picture included a "mystery" like that from the start, I think that J. EDGAR would have been much more effective and, indeed, might have worked.
Nevertheless, it did hold my intellectual, if not emotional, interest.