A power increase from using the low resistance wires is likely not enough to matter, it's kind of like the splitfire plugs, they advertise (or used to) x hp increase, and while in their controlled tests it may show an x hp increase, but in the real world with all the variables of temp, humidity, engine condition, combustion chamber design, blah blah blah, it usually doesn't amount to anything.
In addition to the resistance of the plug wires, the voltage leakage is also a factor (if you've ever opened a hood in a dark garage, and seen an aura around a plug wire, you've seen voltage leakage), so the more voltage that leaks out, the less there is to fire the plug, so if the mixture is a little off, and the combustion pressure is high, the plug may or may not be able to fire

 

Short discussion of plug wire construction as it pertains to stock and non-stock applications.

Short paragraph on the effect of resistance on the firing TIME of spark.

Granatelli wires with 0.0 ohms resistance for $185.

Thread on a GTO forum with some relevant electrical information.

 

The closeness of our coils to our plugs really make all the resistance numbers useless. Unless youre wires are running over a few thousand ohms of resistance not difference will be noticed. In fact I would guess there would be no difference until about 7 or 8 thousand.