Re: I think it would hurt them
Well, to answer your final question, I have always been happy with the service I have got from Andrews and Arnold. Not the cheapest UK ISP by a long way, but as others have said, you get what you pay for.
True story example:
A couple of years ago I was looking at the 1 minute resolution usage and latency graphs you get on their support site and noticed almost continuous traffic right through the night. I couldn't find anything in my network causing it so I phoned them up. The conversation went a bit like this:
"Hmm, let me check you line" tap, tap, tap. "Ah, yes, looks like your router is being used for a DNS amplification attack. There is a page on our Wiki explaining how to change your router setting to prevent that and meanwhile I'll change your static IP and update your domain DNS records to reflect that."
The key point is that (a) they diagnosed the problem rather than asking what version of Windows I was using and telling me to re-boot my computer and (b) they took it for granted that I would know what a DNS amplification attack was. On the few occasions I have phoned their support line it has always been answered by someone who knows a lot more about networking than I do.