Diamond drivers

Okay. I've heard them at shows myself and haven't been impressed either. But get them in a proper audio room, and the sound can be transformative.

Diamond tweeters are for real. While they do make for good marketing and unfortunate price increases, they deliver.
I have owned the following loudspeakers over the last ten years: B&W CDM1, CDM2SE, CDM1NT (Aluminium tweeters), Jamo Concert 8 and 11 (Silk dome tweeters), 804S (Aluminium tweeter), 803D and 803Diamond (Diamond tweeters).
As context for my observations: I am very sensitive to any tweeter harshness.
I like the silk dome tweeters, but not so much Aluminium dome tweeters - they tend to have a residual metallic sound. The better Aluminium versions will only occasionally highlight a distortion artefact, as opposed the less accomplished versions which are almost unbearable after a few minutes.
However the diamond tweeters are clearly superior: better transient response, cleaner, more precise sound-staging, transparent to quality of recording and audio equipment, consistent sound quality across their frequency span. And yet they are easy on the ears - I can listen for hours without fatigue to the 803D and 803Diamond loudspeakers.
I have heard many other loudspeakers at dealers with different tweeter technologies including Beryllium and Ribbon. I haven't heard anything at dealer that would indicate an obvious weakness with the B&W Diamond tweeters. However, as always, a definitive comparison will require extended home auditions.

You are right about the pleasant sound of the Diamond tweeters. But there is more than only the tweeters. The biggest problem B&W has is that they still not make great filters. Wenn you do a test for depth and how wide the stage is, B&W is quite poor. This was the main reasson why I did not want to continue with B&W. I owned the 802N and 800S. The new series still have this problem. Depth ann a wide stage are one of the most excitings parts of highend audio. Wenn this is not that exeptional good, you miss a lot of excitement during listening to your favorite music.

Dracule1
I think the new diamond mid/bass driver is ground breaking. No one else has done what Raidho has with diamond. But I will hold off on judgement of the sound until I hear the D1.

Ground breaking indeed and a complete sonic treat. I have the Raidho D-Series under audition at home at the moment and I maintaining a blog that can be found HERE. Raidho is the only company of Know of that builds its own diamond coated bass woofers.

@Kiwi_1282001

Very interesting and much appreciated! As I'm seriously considering the Raidho D-2 or D-3, I will read and follow the development of your thread carefully.