It's always good to have some of the oil vapors sucked out of the motor. The down side is the inside of your intake, throttle body and intake manifold covered in oil spray. My solution was to buy one of those gitterdun aluminum inline fuel filters from Pep Boys (by the domestic chrome goodies) and put it inline with my cam cover breather outlet and the air intake. Works great and I have already washed it out (English translation: carb cleaner) once. It does it's job.