I listed the steps that were taken in developing the translation
here
The main differences would be:
Extensive feedback/play-testing support from NMA members
3 complete passes on all lines/dialogues
Ron Perlman narrations (the highest quality AI voice available at the moment $$)
Tree-passes on all dialogues (75% of the development time, all dialogues were followed, and polished, 'through' the scripts)
Finally, the tree-passes identified about 85 dialogue/quest bugs that are now fixed in the 'patched' version of the translation.
Slavish adherence to Fallout 1 terminology/styles/language.
Complete 'English' graphics for all game elements.