Leon,
Are you connected with 2.4 GHz or 5 GHz? Have you tried using a WiFi analyzer to see congested channels and setting it to a static one?
I have a 7982 on the basement floor (not mounted) and it provides good signal throughout a 2 story house (basement, main, upper) but YMMV depending on your home construction.
With Spectrum 200 / 10 Mbps plan, I typically get ~200 Mbps when doing speed tests in the same room using an older ThinkPad W520 with the Intel® Ultimate-N 6300 WiFi card (3x3 801.11n).
https://i.imgur.com/Omkf8qi.pngThis is what I get through 3 floors with a Samsung Galaxy Note 4.
https://i.imgur.com/JGgJsX8.pngMy main AP is the Ruckus R500 using Unleashed firmware on the main floor behind a TV and results are similar. I'd try using 5 GHz on a static channel first and see if your results improves.
- Johnson