FWIW I tried the Pertronix setup competitively for a season. I didn't dyno, but telemetry showed my final/top speed before breaking zones was consistently lower than previous years on all tracks in all weather. That would be consistent with what @distributorguy mentioned.
However, I did notice better throttle response when transitioning out of sharper corners. esp. going from light maintenance throttle to WOT. The engine just seemed to "fire better" in that first moment of mashing on the gas.
Those observations could obviously be due to a variety of other things (driver attitude?), other small things changed on the car as well throughout the season... But, thinking back a few years, I thought I'd give my seat-of-the-pants account.
:)