The Dual Rectifier alternator is a very good alternator, nice picture.
The double set of Bridge Rectifiers make the alternator more durable as far as the rectifier goes. The next thing to look out for is the whole unit overheating and burning up the stator, this is where the QuikCool product comes in.
A manager from a large southwestern car audio chain will be installing one in his personal vehicle to test. He drives from store to store and says as the day goes on his alternator charges less & less. If he goes in a store for 20 minutes it charges OK for a while. He will be testing the QuikCool to see if it will keep his alternator charging better and longer. His vehicle has a thermal sensor that cuts the alternator back from charging if it becomes overheated. Also, as the diodes and wires heat up they do not work as well and you loose power. By blowing cool air on the alternator and getting rid of excesses heat it will make the alternator work better and last longer.
I will let you know how it goes.
See Quick Start's QuikCool Alternator Cooling System here:
http://www.alternatorparts.com/Remote_Alternator_Cooling_System.htm