It's not a special edition, it's a director's cut. If it was an SE, the people who did the new effects would have been credited. Therefore, there are no new effects...
If it was an SE, Lucas would explain on the commentary track how he really wanted Robert Duvall's eyes to roll back into his head cartoon style, and fight mutant baboons, but ran out of time and money.
If it was an SE, Lucas would not discuss the logistics of shooting real 1970's locations in the making of doc as a CGI cityscape is shown, thus causing my head to explode Scanners style.
So remember, kids, if you pretend that the movie looked like that in 1971, future generations just might believe you!