We've just had VM M200 for about a month, replacing BT Halo FTTC.
BT gave me 70Mb down and around 17Mb up. Hence I chose M200 to get better speeds for both.
The Hub 3 seems to have an endemic problem where it will sometimes claim you are logged in as admin, even when you're not. You have to reboot or (worst case) factory reset the hub. Not good when 4 people are on video calls, and you need to make a change.
The Wifi on it is considerably worse than BT, even pre-halo, it now doesn't reach the furthest bedrooms at any decent sped. Halo (not even using the wifi discs) was fine. Our house has cardboard walls (not joking) so there isn't much of a barrier to wifi.
So, is it possible to use your own modem/router for VM?
Ages ago, I used a Netgear device with BT.
We do have Virgin TV and phone, so I'm guessing not.
Otherwise, I guess it's turn off Wifi and use my own device (just wifi).
I have Cat5 cabling around most of the house, but this doesn't help the Apple fans that are too cheap to buy an ethernet adapter for the Apple <wotsit> or the phone users