VTEC is an intelligent design that produces better gas mileage, more power, a smoother graph, and more efficiency. It is not like a bolton...it is a characteristic of an engine that gives great benefits, which are greatly expolited with significant modifications. Look at a graph of a heavily modified NA motor, or FI for that matter. Disable VTEC, and examine the same graph. More than a few HP. Granted some loss will be due to the different af characteristics, but the power is lost, regardless.

BMW's VANOS, Toyotas VTTi, etc etc...every car manufacturer has a "VTEC."