We definitely recommend using the SE for any and all body shaving needs. The NickStop™ technology was designed to be used on all parts of the body. The 16 precision fins are there to push skin out of the way and guide any hair to the blade.
For shaving legs, check out some best practices and top tips we have at the link below:
How to shave your legs with a Single Edge
For head shaving, check out our best tips for shaving your noggin at the link below:
Can I use Supply to shave my head?