Our superchargers have a bypass valve that allows the SC load on the engine to be reduced when it's just not needed. The bypass valve runs some of the intake air back through the supercharger to keep it from having to build up when power is called for.
So when you don't have your foot into the gas, the engine acts like a normally aspirated vehicle by running at vacuum (less than zero on the boost gauge) when just cruisng around.
you should be below zero at idle as well, but not a smuch as when you are crusing faster. But when you crack the throttle, the bypass valve closes and the boost starts to build. WOT should see 12-15psi depending on the exhaust on the car. Other throttle positions will see something less, but should be greater than zero if accelerating.
As far as feeling of quickness. high boost doesn't mean high power. On a fairly stock car it is often a sign of restricted exhaust. Also keep in mind that it takes considerable additional HP to make our cars feel "quick". They can feel Fast easy, but "Quick" implies light on their feet. At around 2 tons, our cars take serious HP to feel "quick". If they ever really do.