Ray, I use the Pertronix in combination with a Mallory dis and had no problems with it since using it for a year now.
Advantages: all the prementioned advantages plus a good availability for spares like dis cap and rotor for reasonable prices. Mallory dis is a quick and easy replacement installation, even for a amateur mechanic like me and the whole thing can be reverted in less than an hour.
Disadvantage: not the original look, but see advantages....
I bought the Mallory from Denis Welch in the UK. He delivers it with an additional, strengthened drive dog at extra cost.
Regards