Would rather be a D3 national champ.
Let's be real, outside of the running community, no one in the real world cares about running.
If you tell someone you were D1, they probably think you were a sub 4 minute miler, 20x National champ and national record holder when in reality you probably coming in 60th at your conference XC meet.
But if you tell people you were a D3 national champion, they are still going to think you were fast.
The point is, if you tell the average person you ran in college, they are going to think you were fast regardless of the division you ran in.
The only concept of running that most people have is that a marathon is 26.2 miles (even then some people think a 5k= a marathon); Sub 4 in the mile is kind of a big deal and kipchoge ran sub 2 hours for the marathon.