180g,200g,45rpm,180HQ vinyl etc

I think its down to the care with which they're mastered and pressed. To do it right is time consuming, and time costs money. Add in the short production runs, and costs have to be recovered from the sales of fewer units.

Vinyl heavier than 120gm is - I believe - less prone to warping. 200gm discs have their own issues, though: it maybe that their very thickness puts your VTA out. It's my impression that there are less 200gm issues around these days and that 180 is the norm for "heavy" vinyl.

Care taken in production should mean that surfaces are whisper quiet; I've generally found that to be true. Given a good recording in the first place and good mastering, these issues can sound truly outstanding.

45rpm issues benefit from a higher velocity under the stylus which can translate into a greater dynamic range. I splashed out a while ago on a Classic Records 12" single of "The Look Of Love" by Dusty Springfield from Casino Royal. It had the song on both sides, one at 33 one at 45. The 33 side was very good, but the 45 side had additional presence; the song was not one of high dynamic contrast but the sound was perceptibly more "solid", if that makes sense.

The "quality" production usually extends to the sleeve as well - with thick card being used in most cases, and proper antistatic inners.

Recent issues I've got are from Music-on-Vinyl - The Best of Sade double album, and Eve by the Alan Parsons Project. Both sound splendid.

These issues certainly aren't cheap. I restrict myself to only a handful each year, and I do a rip of them to my music server immediately in 94/24 to act as a casual play and a backup should the disc become damaged.

So - not a dumb question Frostg! But the ultimate answer, like most of hi-fi, has to be "listen for yourself" as only you can determine if its worth the cost. Classic Records, Speakers Corner, Music-on-Vinyl etc probably put out something you'd like, why not give one a go?

Ah - not good! It seems I was lucky with my Music on Vinyl issues. Some magazines (H-Fi+ for example) do review "audiophile" vinyl. In so far as you can trust any magazine review, these could give a guide to sound quality.

When they first came out I bought a half-speed mastered Mobile Fidelity Sound Lab issue of the Previn-EMI Carmina Burana: that was (is) a fantastic LP to play.

Then there was a vogue for direct-to-disc issues. I only ever bought one - some Mozart from the Toronto CO under Boyd Neel on Umbrella Records. A strange disc - a rather close and boxy recording, very clear though, and a pretty underwhelming performance that I put down to the stress of a one-take lacquer cut. It was kind of going back to Emile Berliner et al !