A friend of mine had a set laying around for his BBC, which he saw no gain with. We were talking about the theory behind them, and it seemed like it made sense on the waste spark system. They installed them on his son's Stage 2 car with Stage 2 heads (which was a pain). We were tracing a no start condition. I thought maybe the wires were killing the coil. So they put the old wires on and destroyed the Nologys. It turned out to be a crank sensor wire.
So anyway. Years ago my Harley dyno guy told me to try Nology wires, which are $100 for 2 for a Harley. They put them on his nephews Evo (which has a waste spark system BTW) and picked up 7hp. I tried them on my Twin Cam which isn't waste spark, and saw no gain.