PlusNet are very good, far better than BT in terms of customer service. I've been with them for a while and they have been faultless. Apart from Virgin Media (who have their own cable network) all of the others (including BT Retail) resell BT OpenReach's ADSL or FTTC service.
If you want to know whether you can get FTTC go here and type in your home phone number.