I read the Hoffman forum discussions - with the understanding there are a wide range of opinions shared there, some of which I won't agree with. Sometimes an original pressing has advantages, e.g., the first Van Halen CDs are more prized among collectors than the 90s remasters. Other times, however, the originals are lower quality and the remasters show improvements. Only way to determine is listen yourself, but fortunately, you can find versions cheap and have fun experimenting with your favorite albums.
As for a few tips:
- Look for pressings from 1989 or earlier
- Early pressings (1982-84) are sometimes collectible and can be fun to own in their own right
- Among early pressings, look for distinctive labels -- target labels but also funky designs
- Smooth-sided jewel cases are often appreciated by collectors, since they were used on early pressings
- On later pressings, do your research on the best masters, remasters, and mixes
- Discogs prices are a great indication of what others value -- for example, check out the varied prices for CDs of Jennifer Warnes' Famous Blue Raincoat. You can learn a lot about CDs by tracking the value of a much-appreciated title like that. Other examples: Led Zeppellin IV, Dylan's classics, Hunky Dory and Ziggy Stardust editions, and releases from the major metal bands will give you a feel for what others value in various pressings and masters.
- Condition is really important, for collecting AND listening ... always check for pinholes, which can render parts of a disc unusable
- Japanese pressings, like French wine, can be overpriced because everyone values them, but they are worth it for albums you love -- and great if you can find them in a bargain bin
These are some tips I follow, along with the most important one of buying music I like.