The PCV was invented to reduce emissions. All crankcases and gear boxes are are vented. Not just blow-by but thermal expansion also requires it. The road draft tube was invented to "draw" fresh air through the crankcase to combat the condensation/acid/sludge thing. The end of that tube was at a low-pressure area under the car (when it was at speed) and was connected to the back of the block. This created a pressure differential between the end of the tube and the vented filler cap, which in turn caused an airflow from the vented (somewhat filtered or screened) filler cap, through the crankcase and out the road draft. Even though there's a baffle in the lifter valley, the car spewed unburnt fuel and yucky oil mist stuff. The PCV enabled that air flow to be directed back into the combustion chamber where it could be fired again. The beauty is that the PCV is "load sensing" and will nearly close as not to lean out your motor at idle/low speed but will "pass gas" almost un-noticed while the motor is swallowing lots of air.
If you're not all that worried about the planet or oil spots on the driveway then the road draft would be better than nothing. Who want's nasty-gas or oil in their combustion chambers anyway? I think the PCV system is cleanest and can be accounted for on the power-mode calibration of the carb/fuel map.