I finally watched it last night.
This film is far more abstract, harder to grasp and reach than I expected, but there is no denying that it's Malick's finest achievement, full of amazing images where every scene means something, with deep and philosophical voice-over, great special effects.
Its main story is remembering the oldest son who died at the age of 18 through the second son (played by current day Sean Penn), and it provokes various thoughts about where we all came from and why we are here, what's the best way to live this life, etc.
There is even a glimpse into heaven near the end where every member in Sean's family reunites. This was an absolutely mind boggling moment!
As for the film score, I could hear pieces by Mahler (guess which symphony?), Smetana, Goreki, Brahms, and Berlioz.
I am not sure if I followed everything Malick really tried to convey and for that I will have to see the film again, but for some reason it's been lingering in my mind since I walked out the theater.
It's that great an experience.
John,