Lightweight.

Upgrades: Steve Rogers uses the same shield as from the 1940s – it is made out of vibranium, the rarest and one of the strongest elements in the Marvel Universe.  

Pros: Boomerangable, Vibranium base ensures its bullet, flame and punch proof.

Cons: Easily detachable, an easy target.

Best gadget/feature? Near indestructible.

Makes things go BOOM? When thrown at speed into something explosive, sure.