Yes, the MC501s on 802D was absolutely stunning (with MCD201 cdp and C46 pre). I also heard the M400s in all Classe sysetm on the same speakers - but a totally different room - and the sound was comparable but the MC501s had a very "human" quality that makes music sound perfectly natural. Hard to describe but beautiful to hear. I would go for the 501s and with their 720W into 8 ohms, you won't need more power.
Arthur
Arthur