Nology's claims are rebutted by Magnecor, a competitor - so form your own opinion.
http://www.magnecor.com/magnecor1/truth.htm Scroll down to "capacitor effect wires."
The often-stated concern on Nology wires is that they're hard on the charging system. But, I can’t see how Nology wires will have an adverse effect on the charging system, since the coil primary resistance is what affects the charging system via the amount of current draw.
The Nology wires are an inline resistive-capacitive delay line in the spark plug wires. They have you put in a 1Kohm resistor in line then via the shielding, shunt the spark energy to ground via a capacitor. Initial voltage is about 70% of actual with a typical RC network slow decline. It seems to me that he only time an engine could benefit from this is if the timing is too far advanced.
Still, why install an inline 1,000 ohm resistor with a capacitive shunt to ground in your transmission lines? They aren't installed as original equipment by any manufacturer that I’m aware of. For every claim of an improvement, there are four more cases where nothing happened. I'm in the nothing happened category. I have never seen a bona fide improvement after changing to Nology wires.
Nology coils seem to work fine however. They are designed to be a pulse coil, which is something fairly common in EE design, but have no experience with the design. Unfortunately, even though they are allegedly the same 3ohm primary as the Dyna coils, the Nology Pro Fire coils seem to short and melt out ignition modules on 1994 and newer carburetor bikes.
The criteria for any good ignition wire is:
1. It has very low DC resistance
2. It has very low EMI and RFI interference
3. It is extremely durable and heat resistant
All of these factors are important. Most important is the combination of DC resistance (which cuts spark power directly) and interference, which can cause errors and irregularity in your timing and ECU operation. If you have any kind of electronic ignition or fuel injection, this is very important. You might say "well, my bike runs fine", but even a little bit of interference can misrepresent sensor readings and so on - it's not enough to make your bike not run, but it can and will affect your fuel economy and power. Straight wires (like Evoluzione's) have good DC resistance characteristics, but they have horrible interference problems.
Pressed, I have to say I prefer Magnecor over the other aftermarket wires.