I presently have a Pazon and I have been in communication with Pazon on the ignition and its issues. I purchased the Pazon after my Tri Spark died after 10 years. The advance curve on the pazon is not as aggressive as the Tri Spark and robs some mid range because of this. The Tri Spark robs some mid range over something like a locked advance magneto or the fairly short advance on the stock auto advance unit for that matter. However, the Tri Spark is a reasonable middle ground for advance. An aside, my 70 Triumph still has a Tri Spark in it I bought in 2011 and it is a consistant 1 kick bike.
With the Pazon on my Norton I have an odd misfire that occurs at 3500 to 4000 rpm at part throttle and clears up after 4000 rpm. Using another ignition clears this up. Pazon has agreed to honor their warranty and have me send it back for testing and replacement. The issue is the cost of shipping back to them is steep, and close to two thirds the cost of a new one. Pazon tells me that the advance can be improved with other versions of the Pazon and I believe them, if you are looking at pazon look at the more advanced systems they make my personal opinion is the base lower cost option is not great for the Norton.