JQ

You won't find a lot of Pertronix or Sierra love here on CCF, usually for some reason like "my brother in law's mothers nephews sisters third cousin had a friend who knew somebody that had one fail" 

Kinda seems like the DUI is the darling of CCF, but it seems that they fail too.

The DUI has the coil integrated into the cap which helps to make installation and wiring easier.

Also being a copy of the GM HEI distributor that's been around for a long time, if you have an ignition module failure for example, you can go to your favorite auto parts store and find a replacement module pretty cheap and save your day or weekend or vacation without having to order parts and wait for them to get delivered.. 

Same easy parts finding applies for cap, rotor and coil too.

Then you can replace the cheap parts with DUI stuff later if you want to get back to the original parts.

Price wise, the DUI is probably less than the Sierra distributor and coil and a little more than a complete Pertronix distributor and coil.

Assuming that you have a Prestolite distributor now, you'll need new plug wires with a DUI, you won't need new ones with a Sierra and you might need new ones with the Pertronix depending on what cap you get with the Pertronix. They have one cap for their Flamethrower distributor with male terminals and another with female terminals like your Prestolite has.