The wider ones were aimed for the states that require tire coverage and you don't like flat fenders. I don't like the look of them because they don't line up with bumpers. The narrower ones line up better but still look cool.
I prefer flat fenders because the are functional - allows for more rubber, plus they look cool in my opinion unless you are wanting a full width bumper. Some people don't like the open look that flat fenders give though.