I owned a MC500 for years. It originaly powered some Mirage M1sis, which are pigs at 83db/1 watt with no problems, then more recently my B&w 800ds. It should well with the 801s. If cost is not a problem then the higher power monos would be even better. The 601s are quad balanced and are conservatively rated these would be my pick of the above listed MCs with the MC1000s my second. As for the Krells I have no personal experience other than showroom, but will say Krell is known for low end response and would be worth looking into.