What are the benefits if I could turn my head around like an Owl?
If humans achieved the ability to turn their head 270 degrees they would attain the following benefits.

1. Situational awareness would increase with the ability to hear and view almost 360 degrees.  Making it easier to identify and defend against predators

2. Better skeletal utilization in sports, theater viewing by utilizing chairs that prioritize space efficiency vs ergonomic efficiency.

3.  Relief for side sleepers by making it possible for people to sleep on their back or stomach