For the lowest end of bibs, Black Bibs wins no question. I got a pair of PI bibs from REI when I was starting out and the chamois just felt terrible to ride in, it looked like a mouse pad sewn into lycra. Plus, they were $30 more than basic Black Bibs. I’ve moved up to better bibs, but I will at least still ride in my basic Black Bibs if I have to.
As for the rest, PI probably wins in mid-end and definitely in high-end. If you’re set on Black Bibs, I generally only ride in and recommend to other people the Black Bibs Ultimate, which is their top model, but I consider to be mid quality. The Black Bibs Plus is the same chamois as the basic bibs.