caps have their place. but a cap is basicly just a battery that can discharge a FUCKTON of energy REALLY fast. a local shop used 4 20 farad caps to power their system for 30 min or so just to prove one simple point: caps can be useful.
the "real" reason caps can be useful is to put out more "power" when u decide to play ur system at max volume for ~2 minutes to show off for the ladies, it helps reduce the draw on your alt. but then your Alt has to charge it back up. if ur cap has a Volt meter on it, keep it. the 1 Farad capacity wont do much but it will help smooth out any voltage spikes that may come from ur alt.
oh and using caps as a bandaid is what has given them a bad name. they have their place, and if i had the room, id use one(when i get another system ofcourse...). but only if i could get a good deal on a 20+farad one. plus having a voltmeter that is right next to your amp has its uses as well.
oh again, and caps dont actually have "resistance" so to speak. the power going out can flow MUCH faster than what comes in. but wire is better than a cap.