The RPG sucks. It's worthless without building your entire loadout and skillset around it. This makes it usable.

Damage increased by 12000. It can now 1-hit kill a Bulldozer on DS. Minigun Dozers take 2-shots.

It now has an ammo pickup rate. 0.05-0.1 rockets per ammo box. You're likely to get a new rocket every 20 boxes or so.