Orbi RBK763S - Costco - Replacing RBK53

After the most recent FW was pushed to my devices (without me having any say in the matter), my entire RBK53 system is dysfunctional, replacing multiple devices IP addresses with IP starting '172.' 
This is despite these devices having been setup to have the same static LAN IP address for years.
Right now one of the Orbi RBS50 satellites sports a '172.' IP address and of course shows as 'config sync' and completely unusable - so it's applying this useless IP address to it's own hardware!!

I've tried everything, including downgrading FW to much earlier versions, but the same issues persist which makes me thinkg that there's been a corruption in the software that doesn't seem to care about full factory resets - safety pin waiting for amber flashing power LED then allowing the units to reset/unplugging for 3-10 minutes. Wasted over a day on this and can no longer try to fix something that I do not think is fixable.

Called support, like talking to stooges, denying they have ever heard about such issues, despite informing them it's been reported on their own community forums here!

Thankfully Costco will honor a full return of router products regardless of the fact I've had them for over 3 years, so I will at least get my money back that I can put into something else. 
They currently sell the RBK763S which seems like an upgrade/downgrade of the RBK752 using a dual core processor, oddly huge cache (why?) and seems like a Costco exclusive product because I cannot find any reviews anywhere?

I can't be without a router system, so I have to pick something quickly.
Would the RBK763S be a good replacement, or is it still a hunk of buggy garbage??

The Asus XT8 seems like a good product?

I can order anything from Amazon and have delivered tomorrow then cover the cost with the refund from Costco, so it there's something better for $499 that's not Netgear, I would appreciate some assistance as I am extremely hesitant to purchase another Netgear product as their customer service and post-sales support has to be some of the worst in the industry....period.
I have a 3 level 5500sq ft home, with ethernet access in most rooms for backhaul.

Appreciate any recommendations