I can see believing in the concept behind the technology, but not the technology itself at this time or any time in the near future.
There's a fundamental difference between AFCI and GFCI technology. With a GFCI, we pretty much know for a fact that if the test button works, it will function to prevent electrocution on faults to ground. It's a LIFE saving technology. AFCIs are different. I've never read literature from ANY manufacturer that claims the product is anything but an "added layer" of insurance against fire. Added layers don't have to perform well, or at all. An extra T-shirt doesn't have to keep you warmer when you get dropped off in the arctic.
The other aspect of AFCI design that I find lacking is that the sensitive electronics inside are subject to every power spike, surge or lightning strike that comes along and could render the device useless, with no way to discover this until it's 1) tested or 2) fails to prevent a fire. We all know how diligently and regularly homeowners (and even electricians...) test GFCI or AFCI devices, so I suspect the failure is a more likely outcome. Whew. Now I feel really safe.
What I find most disturbing is that there's really no way to fight back. Someone recently posted a link to the 2014 CMP responses to petitions for changes to the code. Their most common reaction to things like AFCIs or derating on rooftops is along the lines of "No substantial proof was offered." What substantial proof was offered that these devices work in the first place? What we CAN substantiate is the money being made on them. After 2014, that number will double or triple in size.
The saddest thing is that, to my knowledge, there is no other country on the planet with any device remotely like an AFCI that's required. Most other parts of the world have GFP built into their mains and use GFCI protection for circuits used near water. Had the NEC tried to sell me this concept, I'd have jumped right on the boat. I suspect we have a lot more people on the CMP with a lower level of science background than other countries do, and that allowed the manufacturers to do some massive manipulation.