Thanks, Russell. I am unimpressed with the fact that Decca did not encode CDs with the same 48/24. In 2008 they reissued Rheingold in 96/24...
Anyway, I have been comparing some parts of Siegfried and Act 1 Vorspiel is vastly superior than on 1997 issue. The brass, for instance, do not sound so brash and the strings section acquires more body. However, when I was listening to the 3rd Act, at Brünnhilde's words "Oh, wussest du, Lust der Welt", I jumped from my chair as I heard a couple of clicks and thought it might be due to a faulty impression of my CD. I played the 1997 and, at same point, I heard the same clicking noise I had never noticed before. I guess this time I was more focussed, trying to hear every detail. Will continue to explore in a few days. Tomorrow my ROH Ring cycle begins and I don't want to spoil the enjoyment of the 4 evenings by listening to something so incredible that nothing can compare to. Certainly not nowadays, anyway.
Roberto