Also wondering what the benefits of doing the FAA thing????
It's not a benefit but a requirement. Every model/operator (depending on the type of registration) has to be registered before the aircraft is flown.
If hobby registration the person is "registered" and that FAA number is applied to any/all aircraft they fly for hobby/recreation.
If commercial then the specific aircraft (serial #) is registered with a specific FAA# and it's applied only to that one aircraft. Same portal for both registrations and same cost ($5).