the hub5 is ok as long not too heavily loaded. I used to use it a while back. The wifi however is "average". Against a real AP theres no contest. I added an AP (a ubiquiti AC-Lite) and its miles better than the onboard wifi. That being said you can start with just the hub5 and add an ap and disable the onboard wifi so the hub 5 acts purely as router/xDSL modem and get a few more cpu cycles out of it.
(if you are in the uk i do have a pair of the homehub5s i offered for sale but no one took me up on it. I still have the original firmware backup incase u wanted to return them to BT software. Also have the passwords and cards for them. Theres a setup guide linked from the wiki that explains it all)
You can also run AdGuardHome on it for filtering but its VERY tight for space and ram.