The driver's side has collected no oil and thus useless. However, JLT provided me with a complimentary screen to replace in the driver's side that I have not gotten around to install to see if it makes a difference.
The drivers side is the filtered air inlet for the PCV system. There should only be air entering
the crankcase from that side of the engine. Some with supercharged engines say they've had some oil on that side and I can't speak for that. What I can say is that- on a naturally aspirated engine- unless you have an exessive amount of crankcase pressure building up you should never see oil coming out the drivers side.
Either way, I don't use them and never intend to.