funkdoctor, I bought my amp off of a user on these forums. I wouldn't say they are particularly popular, but they aren't completely unheard of. Definitely quality amplifiers, I can't recommend them enough.
60ndown, the link you provided was to a "batcap" which is basically just a large bank of capacitors. Even one of those beefy things, costing twice as much as the best battery you can buy, only provides 8 seconds of continuous current flow. You say, well 8 seconds is more than enough for any bass note, they charge quickly between peaks. That is true, but you are not taking into consideration, the 8 seconds is based on a full discharge. Like I said in my previous post, electricity always flows from highest to lowest electrical potential. So, while that batcap may provide current for 8 seconds, it will only be utilized until the batcap's voltage drops below that of the battery. So lets say you charge the batcap to 14.4V and your battery is fully charged at 12.5V, just randomly choosing realistic numbers. When the bass hits the alternator is instantly overloaded causing the load to jump to the capacitor. At 14.4 volts, completely discharging in 8 seconds, that means that in only 1.04 seconds, the capacitor will be discharged enough that the load will then begin to be pulled from the battery since it has the highest electrical potential. So even with an expensive, large capacity capacitor bank in your car, you are still only utilizing it for just over a second. Due to the properties of electricity, you are not utilizing 86% of your capacitor's potential.
Here's another few points to think about.
If your alternator isn't powerful enough to keep up, then your capacitor, after being initially discharged, will have a very difficult time fully charging again while your system is playing. Depending on how severely your alternator is falling behind, it may very well never be utilized, and your battery will just slowly be drained. Had you spent the money on a deep cycle battery instead of the cap, this wouldn't be a problem, it would simply be an annoyance until you bought a new alternator, but with a regular battery completely discharging and recharging it causes a loss of capacity and eventually will cause it to fail.
If your alternator is powerful enough to keep up with the demands of your system, then your capacitor will literally never be used, ever. It will charge, and just stay charged, since it will never have a higher electrical potential than your alternator.