I couldn't imagine being with anyone else but Andrews & Arnold. Their clued-up staff are a joy to deal with, when you remember how you used to have to face the sinking feeling you get when you need to deal with staff of other ISPs.

I have three IP-bonded DSL lines (ultra-long lines unfortunately). Andrews & Arnold deal with spreading the traffic of a download between the lines according to their speed capabilities. My Firebrick router deals with spreading outgoing traffic between the lines similarly. I have a good-sized block of IPv4 addresses and a huge range of IPv6 addresses.

Because A & A don't offer unlimited all-you can eat deals to all their customers (all though there is a predictable cost tariff available to business customers) the network is not completely oversold and slowed down by contention. You always get maximum performance and A & A publish congestion stats concerning this. This is one reason that the services cost a bit more than inferior “unlimited” networks.

I also have a 3G data-only SIM for my iPad from A & A which works over the Three mobile network, gives me one static IPv4 address and traffic cuts through the Three network transparently, directly into A & A.

One very nice thing is the uniquely detailed A & A control panel website where you can fiddle around with all kinds of dangerous stuff, fix problems, and get a detailed view of performance. A & A have continuous historical traffic monitoring and you can do live traffic captures so you can work out what on earth is going on.

A & A is not as cheap as some networks but you have to pay if you want the best, and this, believe me, is it.