We know Nissan have designed the stock grille to allow adequate airflow to the radiator, the zunsport grilles have been tested by automotive manufacturers to ensure they do not impede this airflow. The flat mesh grilles have been found to impede air flow.
You also forgot to add it costs £100 for a bit of shiney chicken wire, I would expect at least 20bhp worth of better air flow for that
Only messing mate, the finish looks very good
R