Most audiophile pressings are done in heavy vinyl. Then there are old pressings, some of which are heavy vinyl.
I have found most, but definitely not all to be superior to the other pressings. I assumed for the reason of the mastering and extra care in the cutting. I assume the extra vinyl for staying extra flat. That has been my experience. Most every 180gm and 200gm record is very flat. There are a very few I have received that were warped. I probably own a couple hundred audiophile pressings.
I also own quite a few heavy vinyl records that were produced in the ‘60 and 70’s. I don’t think they sound better. But are a hold over from the 40’s and 50’s when most albums were thicker… I suspect from less flexible compounds. Over the decades standard pressings became thinner and more flexible. Some now you can bend to great angles without breaking or warping. Try that to an early 40’s album and it will snap.