To use both your old Google Wi-Fi and the new Wi-Fi Pro, you would need to run two separate networks with different NAT settings. However, you won't be able to use them in a mesh configuration because they cannot communicate with each other due to the 6E band. It's unclear whether you could use an Ethernet cable to connect them, but to the best of my knowledge, the answer is no. I have used the original Wi-Fi for a long time, and I believe that the Nest Wi-Fi Pro is better than the past two Wi-Fi systems, although I haven't noticed a huge difference, maybe a 10 to 20% speed difference. However, I am using equipment that is a little bit older, like an iPhone 13 Pro, and my computer is about a year and a half old, so I don't have any 6E devices yet.The primary difference between the networks, aside from just the bandwidth that they're capable of producing if you have the ability to connect to it with 6E, is that they both talk to each other in the mesh through 6E, which is very fast and easy for two systems to communicate with each other. We are just starting to see new products launched with Wi-Fi 6E capability. In a year or two, there will likely be many more 6E products available.
