I think fibre 150 will be more than enough, as I just tried downloading a steam game to my laptop, which was connected via WIFI to the BT disc in the living room ( which gets a 140-150 mbps download speed, so it simulates a fibre 150 connection... right? ) and I got a 122 Mbps download!
Which is much faster than anything I've had before.
And that was with the BT box connected to that same disc too and tuned into a sky channel. No interruptions or slowdowns 😄
So yep now I know 150 mbps will be more than enough for me.
