Start with the wired path
BE63 is usually the disciplined choice when a 2.5Gbps modem, switch, office, or wired backhaul path is the real upgrade. BE67 and BE85 make more sense only when 10GbE hardware, a fast NAS, a multi-gig desktop, or a planned network shelf can use the extra ports.
Do not buy aggregate speed without clients
The higher Wi-Fi class on a box is not a single-device speed promise. Phones, laptops, adapters, distance, channel conditions, and backhaul decide what a client can actually use. A BE63 placed well can beat a more expensive kit placed poorly.
Two-pack versus three-pack is a layout question
Use a two-pack when the router and one satellite can cover the important rooms with a strong upstream link. Use a three-pack when floors, long hallways, or masonry create separate zones. Avoid placing a wireless node inside the dead zone just because the pack includes one.
When BE67 is the better step-up
Choose BE67 over BE63 when 10GbE ports are part of the plan, you are comparing equal pack sizes, and the home has enough Wi-Fi 7 or wired demand to justify the price difference. If everything downstream is still 1GbE or 2.5GbE, the upgrade may be hard to feel.
When BE85 is not overkill
BE85 belongs in a premium network plan: 10GbE or SFP+ infrastructure, heavy local transfers, a large home, and users willing to tune placement and cabling. For ordinary web, streaming, calls, and gaming, the money is often better spent on Ethernet runs, a switch, or better node placement.