I am not currently setup that way, but I did use an Icon with a pair of Winsome Mouse (Mice?) to drive my Mark & Daniel Minis. Thought an Icon could drive them. Couldn't. Tried two Icons. Still not enough juice. So I used one Icon as Dac/preamp and the two Winsome to biamp each speaker. No complaints about the Icon as a control unit.
Currently using the HDP and a pair of Ref 8 with the Minis. I like the DAC in the HDP better than the Icon but never really did an comparison of the preamp in the HDP v the Icon. I can say the Minis like the Ref 8s. Not as good as my Ref 9 SE v3 with my Mark & Daniel Sapphires, however!