[Shadow of Udûn]

Boromir would never have been able to live with his failure at the Falls.

I disagree. I think, if Boromir had lived, he would have been a changed man. I don't think the change came at his death, but before, when he realised what he had done in attacking Frodo. I think he had overcome his greed and would have acknowledged Aragorn as the king. After the fight at Rauros, Aragorn blamed himself -

Now the company is all in ruin. It is I that have failed

and yet he recovered from this blow.
I love Boromir - he's so Shakespearian, like in Corialanus. Aragorn and Gandalf are simply heroic characters, but Boromir has to fight within himself to find the courage. Doesn't that make his act of courage all the greater?