The Anthem AVM60 pre pro is the same as the preamp processor/DAC section of the Anthem MRX1120 av receiver, not the MRX720. The MRX1120 is Anthem’s flagship av receiver, which retails for $3500 new. The MRX720 is a step down from the MRX1120.
In receiver land, you generally want the biggest receiver so that you have the largest power supply. This will give you the most bass/midbass power and also have smoother sound overall. The increase of watts/channels is the reason why the manufacturers have to build a larger power supply.