What does early detection of Alzheimer's give you, given that it's untreatable? And, isn't ignorance bliss in this case (i.e. the less time you spend knowing about the problem, the better)?
That combined with the relatively high false positives makes this a pretty bad investment so far, in my opinion.
Arguably, there will be no viable treatment unless asymptomatic volunteers get tested with our software so they can enroll in a clinical trail, so why defer the test?