You obtain it early in the game (if you focus on the main storyline), but there are very few times where you actually need to use it. I had a couple sets, but only found a handful of times where it was useful. I prefer to sneak more often than not.
Fine, but starting off, its not like you are going to be leaving the suit behind when you venture off to a new area. You are going to wear it because that is the only way to take it with you as far as I know.
And the "boss" at the end of the first village area you encounter is definitely tough enough to mandate wearing the armor.
TD