Ive heard only bad things regarding sky broadband. My mate was happy with them when he started out on 8mb service. Then he had a problem and it took three months to sort out.
Customer service are like most places these days. Rubbish and inexperienced. When my inlaws were going for it they even told them lies just so that they could get a bonus for signing up a new customer.
But like the guy said, anything is better than dial up.