Max AP6 WiFi Speed (non-pro)

I’m currently using one ceiling mounted AP6 centrally located in our 2000 square foot home with Comcast 400 MB service. We are about to switch to AT&T fiber. Although the house is wired it is largely unused other than for our NAS and Apple TVs. I know from experience the AP6 is capable of delivering solidly over 450 MB in areas not impacted by walls. In fact, the central location delivers over 400 MB throughout the house. My question is what is the max real world Wi-Fi speed I can expect from the AP6. Just looking to choose between the 500 MB and 1 GB service options. There are only two of us so device saturation is not really an issue. What kind of max speeds are you seeing from the non-pro AP6?