Originally Posted by NorthPark

A lot of 'blow offs' have a recirculating option, usually just a hose plumbed back in somewhere in the intake path.

I'm guessing all we have here is a slight difference in the very loose terminology for a blow off valve when it comes to car talk.

Some diverter/blow off changes can have operational benefits, but its most likely that 'upgrade' means louder or sounds cooler. Blowing off to the atmosphere is much louder than recirculating the pressure - note that after market intakes can make the recirculation louder as well.

PROCHARGER WITH TIAL BOV/ INSTALL! SOUNDS INSANE!! - YouTube

A waste gate is used to bleed of excess boost in a turbo setup, blow offs and diverters purge the pressure when the throttle body is closed which can cause problems with the turbine (you've probably heard turbo flutter before, google it)

Procharger actually has some definitions on their website:

ProCharger Bypass Valves | ProCharger




Wastegates can also make a noise, some external waste gates on like big single turbo GNs or Supras can be frightening.

It is to my understanding that a waste gate is not needed on a procharger as it's speed is driven by the engine speed