Yes, good point Virgil. That has been drilled into my head for years. This is why I requested that the shop install OEM bits and we engaged in the dialog. I am open to hear the argument for Toyota OEM in this situation.
My thinking, and Walt/Slee and others, is that I have significantly altered the truck from the OEM configuration by adding all the weight (factory OEM weight 5400 lbs, vs 8000 lbs in current dressed configuration). Making sure that the truck is balanced to compensate for the alterations seems important. Walt has suggested that I need to up my coil over springs and rear springs and re-valve the king shocks during overhaul.
I do agree that things like drive shafts, windshields, lift gate struts etc, where there is an exact replacement, should be Toyota OEM. The shop guy suggested that since I was so much heavier than the OEM configuration and towing at capacity, that the beefier rotors/pads are appropriate. I tend to agree with this logic and had them install. So no going back, but open to the argument if there are important things to consider in the future.