Originally Posted by
ORAC
The advantage of being the first in the world to have a flight tested first stage to inspect and tear down.
Why do you keep repeating that all the time? The Space Shuttle was the first reusable first stage, together with it's boosters. Next came Buran, then Falcon 1, then Falcon 9 then New Shepard and maybe Superheavy in sixth place if there are no other classified reusable first stages of which we know nothing.