At the same time, they really did cut out a lot of substantial stuff.
I read a book on Malick recently made up entirely of interviews with his cast and crew. It was pretty boring to be honest but there were a few interesting bits.
It mentioned that the main battle in the middle of the movie where they're trying to capture the hill was one of three massive battle sequences they shot, but the only one that ended up in the movie. The person (Hans Zimmer I think) was bemoaning that they went to all that time and expense only not to drop it.
They also talk about how after they'd shot a dialogue scene, Malick would often make them reshoot the whole scene without dialogue. That's how Brody ended up being pretty much silent in the movie when he was originally one of the leads.
It also mentioned that Malick's been working on some kind of six hour miniseries version of The Tree Of Life on and off.