Standard brake lines expand a little when the lever is pulled, so a small amount of braking pressure is lost. Braided lines stop this expansion, to a degree, increasing the pressure at the caliper. So there is some advantage to having braided lines, especially on bigger bikes.
Changing the brake fluid will also improve things. Over time the fluid absorbs water making it less effective.
As mentioned upgrading the pads will make a differance, as will cleaning the calipers.
