Better airflow is certainly one. By taking the air intake out of the fender where it is exposed to dust and warm airflow from under the bonnet could be beneficial to fuel economy, power, and even lower servicing costs. Air filters should not get clog up as quick. The Snorkel draws air down from roof level. If you look under the bonnet after a couple of kilometres of driving in dust you will find a lot of dust in the engine compartment where the standard air intake would sit.
Cooler running and cooler looks, the temperature under the bonnet is much higher than you think. If your engine suck air from under the bonnet, it will suck in hot air. This will have a negative on the performance and reliability of you vehicle .The snorkel sucks the air from roof level where it is much cooler.
Lets face it, a snorkel on your 4×4 does enhance the overall look of the vehicle!