BOROMIR:
It is a gift. A gift to the foes of Mordor! Why not use this ring? Long has my father, the Steward of Gondor, kept the forces of Mordor at bay, by the blood of our people-- all your lands kept safe! Give Gondor the weapon of the enemy. Let us use it against him!
Also, when we meet these characters at the first, we can't telegraph the end on them. Meaning... when I am teaching during my acting classes, my actors may be on page 8 or 9 of the script and they begin to telegraph or react to what happens to their characters on page 32 or 33, I have to remind them that on page 8 your character doesn't have a clue that page 32 will happen to him. So, you have to play it as if you don't know.
So, to Boromir it was a weapon... it wasn't until he was appalled at his behavior concerning Frodo that he realized that Gandalf was right.
In Rivendell, Boromir was a good man who was desperate. At the end, at his hour of testing, he remained a good man. Well done, Boromir!
Sauruman is equally fascinating, and fails the same test, but is never willing to see himself for what he became.
Yes... superbly (dare I say adequately?) defended carton!
Be at peace, Son of Gondor.