Previously this was interesting as drive space was a premium. Now it's access speed. So to get our files to and from the cloud as quickly as possible, use compressed files where possible. Julia will deal with compressed files easily.
So before the first upload, replace all .O07 files with .O07.bz2:
$ find . type f -name "*.O07" -exec bzip2 {} /;
Check out the amount of space used / saved:
$ find . -iname '*.O07' -print0 | du -ch --files0-from=-
I'm getting about reduction to 25% original with these.