A while ago, someone on Fordmods has posted before and after dynoplots when upsizing his throttle body. It showed basically no difference at all (at WOT) below 5000rpm, but power does continue climbing above that where the stock throttle body starts to limit flow and power. So it gives a higher peak HP and at a higher RPM, but no difference in peak torque. You would typically get less throttle response at part throttle because of the bigger throttle bore and resulting lower velocity.