With few exceptions, spark plug wires either work, or they don't. As with the 'trick' spark plugs described above, nobody has been able to prove a performance gain by using larger-than-normal or unconventional spark plug wires. They continue to be a popular upgrade, however, with Magnecores being mentioned the most often.
Owing to a number of owners who have experienced longevity problems with cheaper wires, it is possible that the superior build quality of the larger wires means they will last longer than 'normal' wires. This, in itself, would be a reason to get bigger wires, since replacing wires every 6-12 months isn't any fun. Also, plug wires can sometimes be tricky to diagnose, since tests will sometimes fail to reveal the wires are no good.
Nology and others manufacture 'special' wires that are supposed to provide better performance.Dennis Grant has some things to say about 'trick' plug wires. (You should also read the rest of the series.) Most Digesters concur with Dennis that 'trick' wires fall in into the category of 'magic' products.