I had internittent problems with 2 types of extenders which culminated in one failing completely while both types often indicatied low speed when the speed at the hub was good.
The latest ones I was sent were the 'BT miniconnector Kit' which have been absolutely rock solid.
TaiChi - likewise, after a couple of years of troublefree use my BT Broadband Extender 500 Flex has suddenly given up the ghost (router end of the setup, not the one connected to the YouView TV box).
How did you find the miniconneter receommended by Tramdev? Reliable?