Plastic PCV valve vs Metal PCV valve?

Not really on the hose sizes, The factory setup was as such. Positive flow and evacuation of the crankcase is all that matters! Cam lift and more can effect this much, and sometimes a Vacuum pump is required.

Most do not and finding a good balance that gives a smooth idle is the ticket! JMO!
Yes, I read that idle can be quite effected by clogged hoses or stuck PCV valve. Interesting design!