At work I'm sitting near the life-sized cardboard cutout of Darth Vader and I have to say: Darth Vader's costume is shit.
The Stormtroopers are pretty good, sleek segments armoring the whole body. But Darth Vader basically wears a jumpsuit made out of quilted fabric, that looks like it's been sewn together out of an old sleeping bag. A few bits of plastic armour are attached: an awkward-looking shoulder protector and a codpiece are basically it apart from the helmet.
The chest harness has large square boxes stuck to it, with huge clunky switches obviously grabbed from a spare parts box by the props guys. Even in the Seventies and earlier, there were transistor radios with trim, neat components and rounded surfaces: this is crude by comparison.
Fortunately, the cloak covers and distracts from most of it. I suspect that's why baddies wear black cloaks in movies, they're a lot less sinister if you look at their fashion choices.