Do 180g vinyls sound better or is it a myth ?

Most of my listening is not 180 or 200 gram vinyl.  However, some recording are very hard to find in nice condition.  For example the rca living stereos are very good recordings for the most part, but most are destroyed.  classic records made some very good reissues and took great care in the process.  If you have a lot of disposable cash and can afford to buy 10 copies before you get a listenable one, then by all means original shaded dogs can be great indeed.  That being said, most of the time, the original pressings are the ones to have most of the time.

Thanks for all the info, it's great to hear all your views. All this info is giving me a better understanding on everything. 

Thanks again 

Just another scam to get your money. Something could be pressed on 500 gram, but that does not mean it will sound better. I too have given up on these 'new' re-issues. They are warped, full of noise and don't live up to the hype. I like to look for clean original first pressings.  I have bought 180's and 200's till I can find a good first pressing. Plus that's part of the fun. Some of the Rhino's, Analog Production and Audio Fidelity's are pretty good.  To me the new Mo-Fi issues are bad. They don't compare to the old original Mo-Fi's.

180s don't always sound better, but I've got several that replaced some VERY worn albums from high school that popped like a pan of bacon. Cases in point were the Led Zeppelin reissues, Quadrophenia and Stills' Manassas. Jeff Beck "There and Back" and Wings Over America weren't any better than the original, except that it was a fresh, clean copy. That was worth it to me. The last round of Stones reissues are being universally panned by listeners, so I passed.

Sometimes, original pressings sucked to begin with and the new ones were given attention by people who love them (like Led Zep). In the Court of the Crimson King was a bad pressing when I got it in the 80s, and there were several generations of gawd awful CDs. Virgin had lost the masters and consumers got third and fourth generation tape copies (see the King Crimson site for the whole story). They eventually found them and Robert Fripp recovered the original master tapes a couple years ago, and the 200g reissues are wonderful.

There's plenty of information out there. If you're inclined to buy, check the critics but especially the customer reviews. If it's an album you love, it's usually--not always but usually--worth it. Kinda/sorta/on the fence about it? Buy a used copy.

"To me the new Mo-Fi issues are bad. They don't compare to the old original Mo-Fi's."

That's just not true.  Some of the new MOFI's are incredible.  There have been a few duds, but for the most part they are indeed very nice.