A properly matted throttle body does provide gains, but you can't just stick a large throttle body on a bolt-on car.

If you get to big of a throttle body, it probably will feel like smoother throttle at lower rpms, but its going to kill your midrange.

The whole intake path has to be designed to your engines output (or future output). Which is intake -> TB -> intake manifold runner -> cylinder head ports -> exhaust manifold -> exhaust