I agree that in a once-off "lock her all up, chief" emergency stop, braking distance is going to come down to the tyres.
But I also think that it CAN be worth upgrading the rotors/calipers, but only if the originals are actually too small - and especially if theres something bolt on/cheapish enough, then why not?
If the hilux is used as a 2 door sports car more than a ute, or its a tow vehicle, or you go down the piha hill every weekend, then the standard brakes probably arn't up to the task - larger swept area plus greater heat dissapation will improve things alot, especially if the pads are also upgraded.
But on the other hand, if you're not running out of brakes at the moment, then bigger brakes are only going to add unsprung mass and make it handle worse than it already does
