I'm running a Sky Q Router (ER115) and not had any issues with WiFi. Here's a speedtest.net test
from a couple of months ago, which is pretty much on-par with what my router statistics show (On 40/10 Sky Fibre Unlimited). Just done a speedtest right now and got pretty much the same result but with a couple of others using the internet it wasn't quite as good of a representation.
It could be you have some interference somewhere, especially over the 2.4GHz band. Perhaps you were connecting via 5GHz at your dad's house and it makes the speeds much quicker. I know 2.4GHz causes issues for me at my house, with the cordless phones etc.
Because an Ethernet connection isn't a option for me I have a fairly high-end (And expensive!) WiFi card (ASUS PCE-AC88 AC3100) in my PC which is definitley overkill for just a Sky Q router but it works great over 5GHz and never had any slowdown or issues. Mainly wanted it for the external antenna's so I can position them more towards the router.
Edited by tomse43 (Sun 07-Jan-18 16:20:59)