What are your concerns with the Arris G36 and what key outcomes are you looking for? How large of a space? I’m using an SB8200 with Google WiFi (ethernet backhaul - 5 devices) and it works extremely well. That’s overkill for most settings, but with a walkout ranch and some brick walls in key spots, I got creative.

I believe that I am finding the router / modem combo units are not that great!  So my questions I guess was is it better to seperate them for additional coverage

I prefer separates because they truly let you select the components that work best in your environment. For my environment, I would not buy anything that doesn’t support ethernet backhaul. You’ll also want to determine whether you are comfortable with something that is managed “in the cloud” or “on the device”. My Google devices are “in the cloud”. You probably want to investigate what is available in terms of diagnostics/restart and so forth. If I had to replace my devices today, my first choice would be the Google Next WiFi Pro, though I wish they were smaller. I like the simple network management and integration, the fact that I can test/restart remotely, and so forth. Context: We both are focused on “work from home” use cases, some streaming, some home automation. Stability and reliability are key. We tend to use Teams for work and wi-fi calling from home since cell coverage in our area is quite poor. 50+ devices are typically active/on network at any time. I use Fing to help keep an eye on things.