Err... Hmm.. I'm with BT Openworld; My favourite client is with Pipex and, apart from one admin crisis early in his relationship with them, he is quite happy and I believe him.
So, I'd have to agree with the folks above; Pipex would be my alternative choice. But do look at the small print and see what you are or are not getting in the deal. The BT Openworld Spam filter is worth its weight in Gold. And the copper wires between your pad and the exchange belong to BT. So in a conflict situation which would be the first to go?
So, what's the catch and what are you going to save with the cheaper deal? Well, I don't know but I do know that I hate "Yahoo" with a passion and BT have just got into bed with "Yahoo". So the corollary is: "What the Hell am I still doing with BT?"
I dunno! Put simply, I didn't have to change my e-mail addresses and I'm basically bone idle.