Trucks and SUVs are notorious for having inadequate, small brakes. While it may be fashionable to slap on a set of chrome rims, big tires and mean-looking brush guards, these enhancements are mostly cosmetic. Conversely, a set of upgraded brakes will actually add to the vehicle's functionality and safety.
The problem is, the relatively small diameter rotors on trucks and SUVs don't provide enough leverage for calipers to slow the rotational mass of bigger wheels. Hence, trucks and SUVs have longer stopping distances and allow less reaction time in an emergency than cars. Truck brake upgrades, then, provide an additional margin of safety for both truck occupants and the drivers around them.
As with cars, truck brake upgrades are especially critical if you've done any power modifications to make the vehicle faster.
While few SUVs ever venture off-pavement, if you do go off-road, brake parts like braided stainless steel brake lines might make sense. They were originally devised, by the way, for racecars that often had to drive over and through jagged track debris. The steel-sheathed Teflon lines held up better than ordinary rubber lines, which were often severed in such conditions.
Off-road drivers must concern themselves with jutting boulders, snagging logs and other hazards that can create havoc in the undercarriage. A brake part like the braided stainless steel brake line goes a long way toward reducing such worries.