I have a pair of the Reference Cosmos and while it would be difficult for me to accurately explain in audiophile jargon what it is I'm hearing I can accurately say that for me, the essence of the music is communicated so well and so palpably that it is very difficult to stop listening.
I had a very very good solid state amp before the Cosmos' (a Coda 10.5) and I can also accurately say that I've lost nothing in terms of resolution and the retrieval of low level musical details and nuances (in fact they are enhanced). Also, while Fremer had some slight hesitation about some elements of the Cosmos' bass; the Ref Cosmos' bass is absolutely wonderful