Roots style vs centrifugal

[ProTour69GTO]

A big 6-71 blower or an "under hood" blower.
A roots blower develops instant power. A centrifugal charger needs to be wound up (so to speak).

The under hood blower like the ones in mustangs. I also understand that a centrifugal charger is essentialy a belt driven turbo. Frank I dont understand by what you meen by packaging with the centrifugal being its off to the side and all the piping thats needed.

Thanks
Mason