Adjustable PCV valve

I have no blow by. I just haven't been running a pcv . I've seen intakes with ports for the pcv and some have been discolored with oil residue. I understand how a pcv system works and understand that my chain store pcv is probably not right for my engine combination. Just wondering who has done what. I like the idea of a fixed system as I see the adjustable one can be set up for if that's what your combination needs. Thanks for the input.