I currently have a 3000sq ft single story home where I've configured an AXE5300 (3 pack XE5300) in Access Point mode. I have one unit located at one end of the home, near the Spectrum router and conencted to the router via hardwire. In this area I also have Netgear 8 port Gogabit switch holding all my wired connections in that area (NAS, work and personal PC's with doocking stations), network printer, smarthome interface. 

I have the XE5300 in a linear fashion from the house end to end. Most devices outside the office where the router is located, are connected via WiFi.

I use the 6GHz channel currently for the backhaul between XE5300s. (While I'd prefer a wired backhaul, at age 70 I'm not inclined to start crawling thru the attic and opening walls to install wired network connections for backhaul.)

I am getting ready to extend my network out a large outbuilding via point-to-point wireless from house to outbuilding, and then Deco M5's left from a previous house in the the outbuilding.

While there only one person living here, I do have 60-70 devices connected at any time. Including Smarthome, 6x Homepod Minis for wholehouse music streaming, and multiple TVs. And I would like to shift my Apple TV's (three Ethernet versions) to wired connections to the XE5300.

Right now Costco has the BE11000 3 pack on sale. Would I see noticeable improvement if I replaced the XE5300s with the BE11000 units, and then moved the XE5300s to the outbuilding?