Another difference I've found in the aircraft.cfg files is the expanded weights section.  Now that you can vary the aircraft's loadout (and thereby the starting COG variation), addressing the max weight per station gives you a better understanding of weight on a/c performance.

As to FSEditor, unless Microsoft revivies/inlcudes it in an FS9 SDK, "it ain't there".

The config files are text files so going with NotePad is better.

THe main problem with FSEditor was not in what you saw it did, but rather, what it did that you didn't see.

I'd rather see FSEditor as stricly a graphical interface to writing the specific aircraft.cfg, panel.cfg, sound.cfg text file changes, rather than adding parameters over which you have no control.