In Individual and Source I prefer to use "Local Multimedia Object".
The problem occurs when I use "Merge/Compare File": after merging
process all Local multimedia are converted in Multimedia Records, both
in current and merged gedcom file.
I'm using FH 4.1.3, but this probably occurs also in v5, as described
by Mike Tate:
How can I make Family Historian leave unaltered Local multimedia when
two gedcom files are merged?