Thanks!The pilot for the original series was originally broadcast on TV in a 3-hour (including commercials) timeslot. A shorter, 2-hour version was released theatrically (in Sensurround!)
Universal offers three releases:
Battlestar Galactica: The Definitive Collection has the theatrical version of the pilot in widescreen, the entire original series (including the broadcast version of the pilot) in both widescreen and the original full-frame ratios, and the entire sequel series, Galactica: 1980, in both widescreen and full-frame ratios.
Battlestar Galactica: The Remastered Colection has just the two TV series in widescreen only, and does not have the theatrical version of the pilot.
Battlestar Galactica: 35th Anniversary Edition is just the theatrical version of the pilot. There's also a 4K UHD+BD edition.
You did a much better job of explaining this than the review I read. According to Bly Ray.com, there's a new widescreen version of the original series coming soon which includes some extras.