Many, many years ago I had some orange sunshine (per the Shulgin reference, possibly ALD-52, as argued by the chemist, Tim Scully.)
It was by a long way the finest acid I ever tried. Despite being ridiculously strong, there was great clarity and no anxiety. Of course that could just be a matter of potency and purity (not to mention great set and setting) rather than it being a novel chemical.
To further muddy the waters, it seems that there may have been "copy-cat" batches of sunshine, not made by Scully. It has been reported that the mysterious Ron Stark supplied the Brotherhood of Eternal love with LSD from his European labs which was subsequently died orange and sold as sunshine. In fact, it's likely that this was the source of "my" sunshine, as the dates match better.
Stark was in possession of Richard "Operation Julie" Kemp's formula for very pure LSD synthesis. I'm very much in the "purity matters" camp, so that would alone explain the sensational experience I had on "my" sunshine. But let's not go round the purity issue again on this thread.
According to Scully's wiki entry, he's researching a book on the underground history of LSD production. If such a book materialises, it's probably the only way forward on the ALD-52 issue (and likely a fascinating read).
BTW, ALD-25 was first synthesised by Hoffman, and it was the published research that suggested it might have advantages over LSD. Scully got his synthesis information from the Sandoz patent.
As for claims that some of the LSD available today is in fact ALD-25, one would expect that this would have be confirmed by analysis of seized samples (eg Microgram bulletins), unless, as hypothesised, it quickly degrades to LSD. And if that's the case, why bother?