Martin,
I think these are the big ones. I suspect that issues depend on your system. I am using TMG on windows 8, some records are over 40 years old having gone from a PAF Apple IIe system in the 1970's and converted, I do not know how many times.
on files 2 and 3 changes I made.
-did not export the Citation Reference Field - I often had pages of material in this field that was then included on many profiles. When I edit a profile, I may include the detail from this field for a specific profile, all the rest just show the source.
- did not export image and audio exhibts - the image does not get moved, just lots of unuseable reference lines
- modified the repository reference in my system - I show myself as the repository for books, e-mails, etc. that I have in my files. Becasue the reference was to my ID in my system it was not recoginised, this created a "not found" message, over and over.
- fix a data source in my system - there was a bad record in my system, for source, in the distant past a loop had inserted a few 1,000 repeats in an address, I had no idea - took awhile to find , there were hundred of lines in each wiki profile to delete that referenced that source.