There was a time when Milton Keynes had terrible internet speeds. This was due to BT using aluminium for the telephone lines instead of the more expensive copper.
Over the past two years BT and more recently Vodafone have launched their FTTP products (Fibre To The Premises) that allows direct high speed internet access.
I've been using BT's 300Mbit / second for just over a year and it has been pretty reliable. I've only had to reboot the router once as it stopped responding.
Last week I switched up their 1Gb / second product, mainly to see how fast it will go and if it will be reliable long term. Time will tell.
I switched to the faster service on-line without having to speak to anyone from BT (which was a bonus).