One of my neighbors was an engineer for C-H working on the AFCI. He admits they still are not sure what the arc the burns houses down looks like.
I think it is just a distraction to compare this with the GFCI where the fault is easily defined and easily detected. Even that simple device had a bad learning curve. This is a lot more complex device with virtually no standards and no real idea what they are really looking at. Each company has it's own proprietary standard so you can't use a standard tester. I can understand why the manufacturer wants to do the beta test in the customer's home but I am not sure that should be a government mandated process.
