I have been using round section handlebars for years. I swapped out my old bars for these primarily for the flattened tops. Installing them myself pretty easy. The groove for the cable-casing was tucked nicely away. The shallower drop and shorter reach was an added bonus: the cockpit now feels like it fits me just so -- and no more sore hands.
I preferred aluminum over carbon, obviously for price, but these are just a few grams heavier than carbon, and even though it might be a superstition on my part, having had a friend break carbon bars, I feel more secure with metal for this part.
I put these bars on a brand new Specialized Diverge and they work really well with the bike. Very comfortable both in the drops and on the hoods, plus the shaping on either side of the stem makes them even more comfortable when on the bars. Great choice!
I'm considering get another one to put on my backup bike.