Encrypt all the things!

what router did you replace your Asus 66 with?

I replaced my whole home network.

My Virgin Media modem is operating in modem mode... and that connects directly to an Ubiquiti EdgeRouter:

https://www.ubnt.com/edgemax/edgerouter-poe/

I have the 5-port one but you really only need the ERLite-3 as you'll only have 1 inbound cable (from the actual WAN connection) and 1 outbound cable (to your local switch)... if you wanted to use the 3rd port it would be for setting up an entirely different network such as a DMZ that cannot see your local network... which could be good for things like consoles, smart TVs, etc.

The EdgeRouter maintains the firewall, NAT, DNS, DHCP, etc.

Then the EdgeRouter is connected to my switch which is the ToughSwitch:

https://www.ubnt.com/accessories/toughswitch/

I run the TS-8-Pro. The switch is entirely on the same DHCP IP range (from the EdgeRouter) and this means that everything on the network is the same address range. This is pretty cool... because... I have attached my WiFi and my NAS and my computers all to this switch. The funky thing is that my Google ChromeCast (WiFi only) are visible to my cabled computers (with WiFi disabled) because they're on the same IP network.

Attached to my ToughSwitch is the WiFi router, a Unifi AP AC Lite:

https://www.ubnt.com/unifi/unifi-ap-ac-lite/

This provides all of the WiFi in my place and is power over ethernet so a single discreet cable goes to this unit and it's not unattractive so it's fixed to the wall.

It's not the cheapest setup, but it is incredibly rock solid. Since moving to this I have had unwavering gigabit speeds locally, unbelievably strong WiFi throughout the house (and I still get WiFi outside the building (I'm on the 19th floor remember)), it's very secure, it hasn't ever felt excessively hot, I've been able to put the units in small spaces.

And I know stuff.

Like I finally have been able to measure via the ToughSwitch how much traffic goes to/from my NAS typically, or how much bandwidth I actually send to/from the WAN (useful should I move to a place I can get http://aa.net.uk/ as they sell internet connections by bandwidth consumed, and now I'll know).

Troubleshooting the network is a piece of piss as there's visibility of everything, though after setup I've not need to troubleshoot at all because it all works perfectly.

Been running this for almost a year, I don't recall needing to reboot a box once, or having weak signal, questionable speed... nothing.

It's just a different level of equipment.