Stops the rubber hose from bulging when warm, as it has a aluminium braid around it.
upgrading the servo will also help braking as it will exert more force onto the pistons.
Also DO NOT USE SILICON BRAKE FLUID sorry to shout but it is lethal. 
The implication was that braided lines alone would prevent brake fade....
The most important thing in preventing brake fade is regularly change your brake fluid, using competition pads certainly makes a difference but only if they are bedded in properly. Braided lines will give a firmer feel to the pedal but standard lines in good condition are fine.
Competition brake fluid is a good idea as it has a higher boiling point, be careful that someone doesnt try and sell you silicon fluid as this was once regarded as the dogs bollocks but is now known to be dangerous as it absorbs air and we all know what air in the brake lines causes.
