A PCV, affectionately known as a "Pollution Control Valve", LOL, was designed as a way to recirculate unburned gases. Does it or may it have some benefits in other ways, yes.
P C V stands for positive crankcase ventilation
if you are running the engine on the street its a good piece of smog there in no power loss from this devise because the light spring closes the valve when you go wide open throttle and no air flows. its good for the environment because it helps with hydro carbons but i like cause unburnt fuel in the oil becomes acetic and can etch the bearings especially with modern fuel with alcohol. but it is not needed for your engine to run right or strong. also with a bigger cam it helps with a lean idle circuit if you dont use it. improves idle quality without modifing the carb. it can gunk up intake some if the engine is old with a lot of blow-by.