Create a WiFi Mesh System with the NEW Nighthawk EX7700 Mesh Extender

So, I am totally skeptical.  I have been working my way up the extender food chain adding thgem to my wifi: EX7300...to EX 7500..."Mesh enabling pgrade of the EX7300"...now there's an EX7700 available.  I'm skeptical of any improvement with it!

The diagram in the ad shows "whole house" coverage, but the wifi router is off to the one end of the house and covers the far side and upstairs. I don't know how many people have their router on one end of the house and from what I'm reading from the community, many routers are centrally located where cable and cable modem enter the home, like my set up.  So, the solution seems to be  2 extenders. 

I have an EX7500 at one side of the house, good signal, and the "Mesh upgraded" EX7300 at the other*.  I use a Google wifi analyzer and can see the signals.  While of good quality, my wifi connected devices connected to the same or different frequencies (2.4, 5 or 5AC) act like they hate each other and drop their connections.  I can't imagine that Mesh should work like this.  Should it?

Will I and my set-up be happier investing in an EX7500 to replace the 7300 or move up to 1 or even 2 of the forthcoming EX7700's (I feel that's a sucker bet, rember I'm skeptical) or switch to Orbie and have a native Mesh system or even switch brands (that would be like giving up)?  As I said I'm skeptical, though I started off really liking the R7900 router but that was many connected devices ago.

Thank you everyone.

*I returned an EX8000 as it was horrible in my setting, wouldn't even connect to my router.