Pertronix rtr distributor vs. ignitor III

I bought a Pertronix III and their recommended high-output low-resistance E-coil from Summit. The car runs terrible after it warms up. I don't know why, but it pissed me off and my car's been parked for the past 3 months. I've done all kinds of testing, including running a voltmeter to the input wiring and driving around the city, watching the voltage. Then I ran a special jumper wire to the distributor itself. The distributor module is triggered off the distributor's points cam! I never got a good feeling when I opened up the Pertronix box and installed the unit, realizing there was no slip-on reluctor used.

Triggered off the points cam?! I just don't see how that's a solid and accurate triggering device. Man, I wish I never spent the $175 for the Pertronix III and the coil. My car runs so bad after it's warmed up, that I'm worried it will even make it home!