catalyst primer?

[AVS_KRIS]

I'm about to start sanding down the interior pieces...spent about an hour ripping every plastic piece out of my 91 ext cab....Ive been told by many people to use a catalyst primer then sand...they say itll cut down sanding by houuurs...still have to sand but not nearing as much. So who has done this?? Was it easier then sanding everything by hand then primering,then sanding agaain?