I have a AC4200 and get great coverage and speed in my 3 story house. I am a network engineer and trust me you dont want too much coverage outside Never know when the IT guy behind you house decides to see whats on your PCs.I replaced my Netgear nighthawk router and and range extender in place for a Netgear Orbi router and 3 satellites, I now have strong WIFI to front curb and back lot line.
225 linear feat- 22,000 Sq Ft.
Check Amazon for factory Auth. Refurb, almost half the cost of new and every bit as clean and complete.