Are all intake vents the same in terms of quality and performance?

Intake vents in general are interchangeable.

Intake vents in general are interchangeable. The driving force for intake vents is the wind and high static pressure. Any opening is an intake if the static pressure at its opening is higher than the static pressure in the attic. The soffit area and the roof's lowest edge on the windward side of a house has a high static pressure; therefore, any opening in the windward soffit or roof's lower edge will be an intake. The only difference would be the net free area the vent is specified to have based on its design. The more net free area; the more air will pass through. Air Vent's Edge Vent, Vented Drip Edge and Continuous Soffit Vents all have 9 square inches of net free area per linear foot.