Royce said it will run cooler. I didn't know that. Possibly that could be why it has lasted, but I'd be inclined to run it the way Pertronix suggest. They designed it so they should know. Others seem to not have a problem so perhaps the problem is with a newer batch of coils, rather than the flame thrower coil in general.
On the subject of pertronix, I noticed no difference whatsoever when converting to the ignitor II and flamethrower II from points. No easier starts. No smoother running. No better throttle response. No better mileage. Nothing. It wasn't any worse but certainly not what was advertised. When I managed to fry the P II and reinstalled the points, it felt better with the points. That is my only experience with Pertronix so perhaps my opinion is not justified, but I am not impressed. This was also in a fresh rebuilt distributor, so there was no worn out, sloppy components for the electronic pickup to mask and provide a perceived increase in performance that can be had by simply rebuilding the distributor.
Never had a problem with the coils. I still have the flamethrower II somewhere and I have a Flamethrower with my points distributor for a backup.
I second Drylakes recommendation of Performance Distributors' ignition. Though the HEI style (che vy style) is impossible to use on a Y block, A Duraspark conversion with their Dyna Module, inferno coil, and livewires is fantastic. That's what I've had for about 5 years now, trouble free and I did notice a difference with that, much less cold natured, feels stronger from idle to about 2500. The cold driveability is the most impressive. On the coldest of days we get in Georgia, I start it and it is ready to go. With the points and Pertronix it would spit and sputter on cold days if I didn't let it warm up a bit but this is start and go. And by the way, I don't recommend that, you should still give the oil and fuel system some time to warm up but it is an option.
Mileage may have increased but i did a carb swap before I could check so I don't know how each contributed to that. That combo did get a 2mpg increase.
However, there is a significant difference in price between that and Pertronix. I think it boils down to the old saying, "you get what you pay for."
Lawrenceville, GA