I'd never have gone to Yale because it was a poor fit for my interests. That's different from being a poor school. Overall school quality is less important than fit. Given my interests, I would have pick Stanford over Yale (and in turn pick Caltech, CMU, or Georgia Tech over Stanford).
That said, Yale is a phenomenal experience. It's very academic in the classic sense -- deep, philosophical discussions, and thoughtfully exploring topics in a way that's increasingly rare in the fast-paced elites. It gives a lot of what people assume they'll get out of a small liberal arts college (which is different from the reality; most small liberal arts colleges are expensive and horrible).
I have little knowledge or Princeton. I know both Harvard and Stanford in great depth.
I have significant experience with HYP, less-so with Stanford. I don't think I am a naive audience, I know many people from these schools and have attended classes, either due to being a student there or online videos in the case of Stanford & Princeton.