That is a good point about how many are still going to be working after a few years. This article is from the IAEI magazine and they found out in my area about a third of the device type GFCIs and over half of the breaker types were just "looking pretty" but did not work.
http://gfretwell.com/electrical/gfci1.pdfThe AFCI is more complicated than a GFCI and would be more susceptible to surge damage.
