Heavy – it is basically a flying tank with modular deployment capabilities.
Upgrades: New weapons-based modularity – ability to discard of used parts when needed and able to reconfigure on the fly.
Pros: Arc-reactor-powered core – capable of flight, firing repulsor blasts, anti-tank missiles, anti-personnel guns – and fully deployable portable armour.
Cons: Needed to help power Tony Stark's heart, reliant on energy source.
Best gadget/feature? To be revealed – it will "build upon the cool suitcase armour deployment and play a major role in the movie."
Makes things go BOOM? Oh yes.