Calling Helm of Saint-14 overrated is a bit of a reach, in all of year one it was the go to Defender exotic, particularly in add control situations. However, year two PVE seems to keep adds at a greater distance, diminishing its usefulness. So yes, at this point in Destiny, it's no longer essential, but is still very useful; it's gone from my number one to my number two. That being said, Ruin Wings have since overtaken it for overall utility, and it's what I run all the time except at Golgoroth. It will be interesting to see what year two Armamentarium will be, if it's simply a second grenade charge that will be highly disappointing; but I highly doubt they'll keep the more Special AND Heavy ammo perks intact.