I'm not saying their abilities aren't "extraordinary" or at least very impressive compared to what one might naively imagine. I am more saying that people who spend endorsement efforts in other areas also tend to gain enormous abilities and so these are "normal" extraordinary abilities.
The point others have raised about these people not having abilities in other areas goes beyond this "unique talent" "not transferring". The point is that the people with these "abilities" spend a fair portion of their waking hours maintaining them. The memories may be accurate but they're "honed", time is spent codifying them.
Most specifically, the memories are clearly very different anything "photographic".
Just consider, if a person actually a video tape of their entire life, using said tape to answer questions about "what happen on day X" would take a few hours of mental processing. These people answer such questions instantly.
They've made themselves "experts" on one subject, themselves, and the ability give instant answers on that subject is a clue to this...