MMM - interesting stuff. I'm in the process of changing back from World-online to BT. I think world on line's service is cr*p - have you ever tried getting through to their customer service line???
One thing to consider, even though it has nothing to do with internet access: We had a very disturbing threatening phone call recently, which scared us both silly. We automatically rang BT who put us through to their 'nuisance call' dept. only to be told that it was world on line's responsibility to sort it out. It hasn't happened since, but I do think that BT offer services like that, which other providers don't, but which we take for granted. Just worth bearing in mind.
I agree with Ed. BT ain't perfect, but there really doesn't seem to be much alternative.
My tuppenceworth,
Catrin