My understanding was that BT hh6 (Wi-fi router) was fibre optic - albeit using FTTC. We have the HH6 and it works fine throughout our large house upstairs and downstairs although being a modern house all the upstairs walls are simple wooden structures and not bricks and mortar. Works well, works all the time. We are two ‘older’ users with no kids so our usage is modest. The HH is next to the master socket, which is next to the smart telly so the telly is connected directly to the HH by a short cable. Prior to that the telly was connected to the HH via Wi-fi - worked very well all the time. We watch Netflix effortlessly in HD. We are paying for the basic BT fibre optic package - infinity 1. Over the last 12 months they have upgraded us from 35Mbps to 55Mbps and last week they said they had upgraded us to 75Mbps all done automatically with no requests from us and no increase in our monthly payment. The basic 35Mbps package was always fine for us and our usage, and I would not have paid for any of these upgrades. Unless you anticipate lots and lots of usage I’d go for the base package. BT are always doing deals, especially to attract new customers or to retain existing customers who are about to go ‘out of contract’ so if you decide to stick with BT I’d give them a call and very gently grasp their testicles.
As a starting point why not test your existing up/down broadband speed using BT’s speed checker:
BTW Performance Test