Vader is cooler than Iron Man because:
Vader's powers come from WITHIN, whereas Iron Man's powers come from his armor, which is from without. He who's powers come from within is always a greater man than one who's powers come from without.
Iron Man can run out of fuel or battery power. Darth Vader never runs out of power or energy.
Iron Man is an alcoholic, a man who therefore has no control of himself, and who was played by that obnoxious coke fiend, Robert Downey Jr.,who got CAUGHT twice for doing coke, and after the judge let him off easy the first time, he STILL kept doing the coke and got caught AGAIN... lame loser... whereas Darth Vader was played by the great James Earl Jones,who is a MUCH better actor ,and David Prowse, who is a body builder, and a dancer, who could indeed out dance Robert Downey Jr. I think David Prowse is also a martial artist, as well.
Darth Vader can sense things with the Force for awesome psychic powers, which Iron Man cannot.
Remember when Han Solo shot at Darth Vader in Bespin and Darth Vader deflected the blaster bolts with his hand, and then took his blaster from across the room? Same thing would happen between Iron Man and Darth Vader. Darth Vader would just strip Iron Man's armor off using the Force.