So beyond being purple... higher flow rate? I know you can buy adjustable versions of our non-adjustable PCVs, wherein you set the various idle and off-idle flow rates. But normally these are calibrated to the carb, such that I'd think a PCV option would normally require a different carb tune.
Maybe it's just an overall capacity thing, it can flow more when open?
Which brings me back to why I asked, I suppose, which is that I don't know!
