This is a long thread and I haven't read it all, but does the recorder have any backup features, or issues with saving files in case of power failure/batteries?
Short-short answer, yes, Steve tested that. It has to run for at least 1 min I believe before the backup starts working...
Yes, that seems correct. I think what can be concluded is that it seems to save in one minute chunks. I'm not 100% on this, but I think what my test showed is that if you happen to lose power, say a few seconds after the one minute chunk is saved then you might only lose a few seconds of your recording. If you're less lucky and lose power towards the tail end of that time frame, you might lose up to just short of a minutes worth. But seems like the most you're ever exposed to lose is a minute of your recording, which I find to be adequate for my needs, especially with redundancy in powering. With redundant power sources, I'm far less likely to ever have to worry about a complete loss of power while recording. For example, I'm powering my F8 from the rear 12V connector from an external battery, with the AA battery sled acting as my backup power supply.
Incidentally, I've also confirmed that there's complete transparent changeover when the unit switches between external power and the battery sled. No clicks or interruptions in the recording of any kind.