I think you could perform your own A-B benchmark test. Find an album you like that just happens to be available on old school vinyl, and has been re-issued on the new 180g vinyl. Give them a home audio test in your own space and see what you think. Give us a report.
I'm going to wager that if both surfaces are in good repair, and come from similar masters, they will sound pretty much the same. I haven't read anything that says the new 180g vinyl is "better sounding" although it may be a touch more durable. The old school and the 180g pressings are still made of the same stuff: the newer ones just are a bit heavier and have a touch more durability.
Try it out........return and report
I'll take that wager and raise it by $500.
The master is only part of the equation when buying an album- the stampers have a huge effect on sound quality and some records that came out of the pressing plant were made from stampers that were used for far too long. That's because the record companies wanted to squeeze every penny out of their investment. The vinyl, which is just PVC, has carbon black added to make it black. Unfortunately, it also makes the vinyl incredibly abrasive. It's the same material that makes tires black.
I don't know if anyone has experimented with other materials, but I wish they would. The abrasiveness is one of the reasons LPs are noisier than they should be.
There's a bit of bad info about what 180 gram vinyl is- it's not the type of vinyl, it's the mass of the glob used for the album. The material itself is called 'virgin' or 're-grind'- virgin is pure material with no foreign matter (to the extent that it's possible to prevent anything getting into an open-topped hopper) and 're-grind' is albums that didn't make the grande for some reason, so they go into a grinder before going into the hopper. That means labels and sometimes, part of the cardboard box they were in. I have or had at least one album with a chunk of cardboard that was over 1/8" across and visible from one side, or both.
Unfortunately, we don't get a choice in the vinyl most of the time- usually, it was only when someone came out with an 'audiophile edition'.
If an LP sounds bad, it needs to be returned.