I upgraded my modem from Comcast - so now I'm getting 2 gig down / 300+ upload. I need to get an extender or 2 to get usable signals to the upstairs, but I think it will work out.
so far the 2 gig is doubled my previous down speed...the 300 upload is 10x my previous upload speed. Upload speed was always bad and they never increased it. But now with twitch and youtube streaming they had to increase the bandwidth some.
Wouldn’t recommend an extender as it just weakens the signal elsewhere, but you need a mesh router with at least 3 WiFi points (like the eero as mentioned above). Covers about 4500 sq ft. Speed won’t matter if the signal isn’t reaching where it’s supposed to.