OK: in my system the best HDCDs sound noticably better than the best non-HDCDs.

The same is true for XRCD and super bit. It seems less true for the so called gold CDs.

The problem is that the worst HDCD, XRCD and Gold CDs sound just as awful as bad standard CDs.

The difference is fairly small on an absolute level but little steps are pretty much what audiophilia is about. The differences I perceive (between two good recordings) are similar in amount as those between two decent cables. Not as big as the difference between mass market cable and a much more expensive one.

Please note that my ability to hear these differences did not exist with my older all Denon 20 bit player and integrated amp system. I was pretty much in the "expensive cables are snake oil" camp. Now that I own a system that is close to 10 times the price of the Denon stuff suddenly I can hear small changes far better - duh.

The very best standard CDs recorded very carefully by a company, a recoding engineer and a band that cares about sound quality are very close to the best of the better formats I have heard. IMHO only abut 10% of all recordings qualify on a good day for these accolades.

In other words the industry as a whole could do a lot more for us in controlling quality than they could by pushing yet another "better" format at us. By the way this is true even for recording sessions that are 50 years old, when carefully done they sound very, very close to the best (I've heard) available today.