I'm less concerned about the usable I/O life than I am with the ability (or lack there of) to recover if and when flash memory fails -- data recovery is very grim on flash memory in my experience.
We recently had a CF card die in the time between taking it out of the camera and trying to load it into the computer. It was the only copy of a section of photos, so we had to attempt data recovery with it. Nothing was recoverable -- the memory chips had become damaged and the tiny electrical charge responsible for the storage had totally dissipated. Needless to say, my co-shooter now absolutely knows how to configure the camera for dual card writing (she had not correctly turned it on at the event in question).
We recently had a CF card die in the time between taking it out of the camera and trying to load it into the computer. It was the only copy of a section of photos, so we had to attempt data recovery with it. Nothing was recoverable -- the memory chips had become damaged and the tiny electrical charge responsible for the storage had totally dissipated. Needless to say, my co-shooter now absolutely knows how to configure the camera for dual card writing (she had not correctly turned it on at the event in question).