Between a double edge razor and a straight razor, which one will give the closest shave?
On a more serious note, it's going to vary from one individual to another. For me, the DE beats the SR consistently. The reason? Mapping the grain of my beard on my neck, while it resembles a satellite photo of the Carribean during hurricane season, is predominantly left-to-right. To shave ATG with a SR or shavette, I need to hold a 6" razor vertically and there just isn't that much room between my jaw and my clavicle. I wind up doing it at maybe a 45 degree angle. That just doesn't work as well for me as a DE with a blade 1.5" wide that can do a real ATG. I'm sure if I was more motivated, I could find a way around it, but I have multiple DEs and blades that make it easy to shave with a DE or SE, so why bother?