Local ISP Advantages

Local ISPs do not outsource their customer support. If they do, they're no longer considered local. Consequently they will generally be a lot more reachable than their national counterparts. It's usually not too hard to find a real, local person who cares about your problem. Local ISPs will sometimes (surprisingly) utilize more advanced ISP technology than their national ISPs. This is true for the same reason that smaller companies are usually responsible for technological advances -- smaller companies usually move and adapt more quickly. Local ISPs will also sometimes have better latency due to their proximity.