I used a Rogers modem + 4-port switch (for more ports) for ~2.5 years, situated in the middle of the main floor. Reception was medium at the outer edges of the property (i.e. it would detect 2 of 4 bars, but it kept dropping video feeds.)
Facebook videos keep buffering, and also issues with the router (i.e. Rogers modem) holding onto IPs too long after a hang and not redistribute them and/or assign/reassign an IP. It was painful.
I then went straight to Rogers Modem (crippled the wifi part) > Asus router > computers.
Most if not all of my problems solved with the Asus RT-AC3100. Speeds do seem muuuuuuch faster too -- not that I run Speedtest all the time.
One of the major benefits you get with a separate (new/newish) router is the ease of network management ... With my router, Asus has an app that lets me easily see, and configure things. I can limit bandwidth, kick the wife off the network if she's watching KUWTK
Problem I'm finding is I'm starting to run out of physical ports, AGAIN