Have not heard those, but the Gustard R26 is a very good sounding R2R that I thoroughly enjoy, especially for tracks that are more… “musical” rather than gut punching rock etc.. I find the fast delta sigma to sound better for 24/192 tracks of “busy” songs blasted at, probably too, high SPL.
Sorry if I don’t have all the jargon or terminology down pat.. just saying.. the R26 sounds better than the delta sigma(it is an smsl su-10) for some music and the delta sigma sounds better for others.