I am a retired electrician. I haven't installed AFCI breakers. When I first heard of them "detecting an arc signature" my concern was whether they could distinguish an "arc signature" between a genuine arc fault and that of an appliance with a commutator and brushes, such as a vacuum cleaner or a power tool, etc. I recently spoke to tech support at a major load center manufacturer and posed this question. I was told that they continually improve the AFCI breakers and are well aware of the "nuisance tripping" problem. I was told to look for the latest manufacturer date on the product.
Nearly all the branch circuits in a residential dwelling require AFCIs, according to the NEC. How are they working out in the field?