What speeds do you get hooked up directly to your Arris?

I use Asus gear in AiMesh mode with wired backhaul. Works flawlessly.

People recommend against mesh mostly because most people use it wirelessly. Since you have a hardwired backhaul, I’d recommend something simple like eero or Asus Zen line. You can go APs with a router/controller but I think mesh is the simplest way to go and you can plug the wires right in and they’ll go.