Speeds are good. Accessing via wifi we’re getting ~ 40mps. (This is about 8 times faster than we were getting)
Using a wired connection (direct into the router) it peaked at abut 56.4mps which is slightly better than BT quoted us.
At present BT are the only people offering the service.
Both PlusNet and TalkTalk are also offering the service. The speeds offered seem to vary by vendor.
A list of fibre suppliers (not necessarily offering a service here) can be found on the Openreach site:-