Those Metropolis bars and similar do change your wrist position but your back doesn't move much, because they sweep forward a bit first and aren't any wider. The sweep is clearly less than 45 because the grips make more than a right angle with each other. I like the idea of them since wrist angle is my usual problem when in commuter mode, but the straighter bars seem more appropriate once you're on the trail.

Classic cruiser handlebars come in several widths (24 26 28) and sweep back more than 45 deg and do not sweep forward first, so they set your hands a good bit wider and sit you up. They are usually chromed or black painted steel, not aluminum and are pretty heavy.

For some reason catalog or website sales photos often don't show swept bars to their best effect, they tend to line it up straight or something and lose the sweep or the rise. Do a Google image search of whatever you're considering to see it in its natural environment.