Blue sky:
I idid perform the exact comparison you are asking...at Audio Element in Pasadena, CA, I critically evaluated the Ayre Mx-R 20 mono blocks and compared them vs the D'ag Progression Stereo, vs the D'ag Momentum stereo...I thought the Ayre and Progession were pretty close, but preferred the D'ag, but felt the Momentum Stereo S-250 was in a different and better place, and ended up purchasing a new D'Ag Momentum Stereo, which significantly bettered the Hegel H-30 stereo amp it was replacing. I am really enjoying the D'ag, using the VTL 6.5 ii tubed pre, it makes for a wonderful combo...some also use it with the ARC 6 or 10 preamp...all good choices, but as mentioned above, you need to audition with your gear, and your ears, and wallet, and make the choice that works best for you. I am now very happy with my gear, and just enjoying the music. By the way, no reliability issues, and it looks as good as it sounds
Best,
Bob