i know how to replace it, but do i have to, or are good for a long time, what do they do in laymens terms? is there high perf ones out there, how much are they
you should replace them when you do a full tuneup. they are usually less than 10$. I have never heard of a HP PCV valve and I dont think you would get any kind of benefit from one. they are usually good for 20-30k.
they allow the crank case to ventilate. all engines get some kind of blow by past the piston rings. these compressed gasses get down into the crankcase and can cause a pressure buildup which if not vented properly can blow seals and gaskets.