1. 'S' means sample verification which compare small portion of each files, while 'F' means full verification which compares all data of each file. With 'F', it'll take about 2 times longer than normal back up.
2. The 'update' function is incremental copy.
1) Back up a memory card.
2) And don't erase it. Just take another picture.
3) Then back up the memory again.
In this case, instead of copy all data in the memory, just copy added files only.
That is the 'Update' function.