Just so, RodWolfy!
Asym in a SB is less pronounced because at 52" it is relatively narrow. Most hammocks are full width of the cloth, which is about 60", so they can have a generous and roomy diagonal. The SB diagonal is closer to the centerline because your feet and head reach the edges sooner than with other hammocks.
Being relatively narrow also limits the shoulder squeeze. It can only squeeze a little, because there is not a lot of extra fabric with which to squeeze. That attribute also yields the nice view on each side; unlike a HH, there is no wall blocking the scenery.
At one time, I thought I would never have another 'boughten' hammock, that I would make my own from now on. Then, I got a Switchback. Not only do they have a unique geometry, but they are made very well. Even Thing1, who loves DIY hammocks and sleeps in one every night at home, uses a SB Lighthiker when she needs a bugnet!
"We must, indeed, all hang together or, most assuredly, we shall all hang separately." - Ben Franklin