I like this question despite some of the d*bag comments typical of LR posters. This might be a good question for HS athletes to ask themselves when thinking about their future and their higher education goals.
I think you could and should feel pretty good about yourself with either accomplishment. However, I think I would rather be champion than just one of the top guys. But I say this as a guy who really didn't know what he wanted to do with his future and used the time in college as experience and part of my maturing process before heading out into the "real world." If I had had a pretty good idea of what I wanted to do after college, then a more business-like D1 program might have made sense and D1 All-American would just have been a stepping stone in the process of becoming successful outside of sport.
I went to college before the age of the internet and didn't come from a family with higher education experience. I didn't know the difference between D1 and D3 in real terms. I wanted to compete and could only imagine myself competing against the very best. However, looking back on it now, D3 would have been a better fit for me since I wasn't a national elite caliber athlete. Since my focus at that time was really more about athletics than school and a future career, I think D3 would have been a better experience overall.
Athletes like Nick Symmonds and Will Leer, in terms of having an athletic career, show that it is possible to become an elite level athlete without being thrown into the deep end of the D1 athletic pool and being forced to swim without the possibility of ever being given a life preserver and allowed to rest while gaining experience.