I've been with Tiscali, Demon and now Xilo.
When I was with Tiscali it kept disconnecting, when I was with Demon the support was awful (Online support chat for example, they would ignore me until I said "Hello?")

I'm now with Xilo, and I'm very happy. The support has been great, the multiple IP addresses for no added cost is fantastic.

When I was with Demon I asked them to reset the sync rate, and they refused. I've been with Xilo for just over a week now, asked them to reset the sync rate on Sunday, it was reset on Monday, and my connection speed has gone from 50KB/s to 160KB/s :)

The reason the speed is low is because of my very old phone line, not because of Xilo

I would recommend Xilo any day.