If a weapon upgrade only goes up to 1 (such as making a weapon automatic or unlocking the alt fire) the upgrade station will not display "Enabled"/"Disabled" instead of 1/1 and 0/1.
Any collectable you pick up will now be available in the "Collectables" tab.
So any of the books found for example will be available from there once they've been read once, you will no longer have to go back into the level to read it.