The Gigabyte B550 AORUS PRO AC wins in 7 out of 14 comparable specs, with 5 ties. Its biggest advantage is PCIe x16 Slots (200% better).
PRO B660M-A WIFI DDR4 wins in 2 specs (MSRP: 33% better).
Recommendation
Choose B550 AORUS PRO AC if you want the best overall performance — especially pcie x16 slots.
Choose PRO B660M-A WIFI DDR4 if msrp matters more to you.
