The exchange was recently upgraded, just before I got my circuit, although I'm not sure in what way. But when I first got the circuit a few months back they basically said that anything under 8Mb would be considered a fault. Well I've never achieved above 2Mb, despite numerous calls to to BT's call centres.
So initially I'm trying two things, obviously one is moving to plusnet, and the other is the purchase of a billion 7800n (switching from homehub v1). I'm under no illusions about a dramatic increase in bandwidth, all I get are lies on that front, but I'd be quite pleased with a lower and steadier ping. And if I'm really lucky then maybe the infrequent line drops will stop as well.