I'm a mechanical engineer, and the scientific principles in the description of that device are pretty legit. And from their dyno charts, it seems to work at almost all rpms. Basically, when the intake valve opens, the piston is sucking air from a small "prechamber" in the intake runner, which starts at atmospheric pressure. This is obviously easier than sucking against air that is already at a vacuum. As the piston keeps sucking, of course, the pressure in the intake runner decreases, but the piston ends up wasting less work on its way down.

This is one reason that diesels are more efficient than gassers - we don't have to suck air past a throttle plate. And since we can meter the amount of fuel injected and don't have pre-ignition, we don't need all the PRV devices this group just invented.

BMW is using this principle in their valvetronic engines. They don't have throttle plates - they can infinitely vary how much the intake valves open.

I remember giving a couple hitch hikers in suits a lift through the city who had put all there money into a carburetor they designed (and had with them). It also was a venturi type system. It swirled the intake air and at a faster rate than normal which provided better ionization. They were after better fuel economy though.