AC3000 mesh wifi system (rbk50) vs ax6000 wifi mesh system (rbk852)

I went from RBK53 to an Arris AX110000 mesh. Maybe someday I'll buy a RBK850 system to test but not yet. 

Worth it? not really.

I'm on a gigabit connection in about 3200sqft. Also, my 4k TV's, my server (x2), and my primary pc are all hardwired into my network. So there's a load off the wireless network.

I don't really notice a difference in performance. Its only when I'm doing peak performance testing and using an AX device that I can see a difference. 

For the vast majority of the time, no, I don't think so. The RBK53 was a pretty solid system and provided 200mbps+ anywhere in my home. That's more than enough for the wireless devices.