I've only had one brake fire while cutting through multiple brad nails. It was my own fault for not bypassing the safety mechanism as I knew that I was going to cut through the brads. The only saving grace was that I was using a crappy blade but it was a pain to have to wait for another brake cartridge before using the saw again. I initially thought about buying a back up brake but at ~$70 a pop, I am still only using one regular brake cartridge (and a dado cartridge).
The only other issue I encountered with the PCS saw was a code to adjust the brake distance from the blade and despite multiple unsuccessful tries at resetting the correct distance between the brake and blade, I called customer service and spoke with Darren, who immediately identified the issue, which is a known idiosyncracy of the PCS. If the riving knife (or blade guard) is removed from the clamp, the clamp can sag and drain the radiofrequency telling the cartridge that it is not adjusted correctly. The fix (for me) was to simply saw off a second riving knife that I had and insert it into the clamp to hold it up for dado operations. Darren mentioned that a thin piece of wood inserted into the clamp would accomplish the same thing.
I love my 3 HP SawStop PCS saw and would definitely buy one again.
Tom