Ive owned top of the line stuff from Sportful, Castelli, Assos and Pearl.
The Castelli and Sportful both had stitching start to come undone at the chamois within a few months of wearing. This was their good stuff too (Premios and LTD). Besides the stitching issue, I really like the Sportful’s. The Castelli chamois placement doesn’t get along too well with me, but that’s a personal preference thing.
The Pearl leg grippers stretched out and became loose way too early.
Assos is by far my favorite out of those brands. They are really just excellent. My go to brand for value though is DHB. Their Aeron line is nothing flashy or special, but they are consistently good and fit me well without breaking the bank. Their newer 2020 stuff is a big improvement over their earlier stuff too. When on sale, which is pretty much always, you can snag their Aeron or Aeron speed bibs for 60-80 bucks and they blow everything out of the water from that price range to even over double that price from what I have personally experienced.