I do not have a copy of the ABC version to directly compare to, but my understanding is that it was extended to fit 3 hour time block and it included the extra scenes as in the Director’s cut DVD, and nothing was missing. I did see it several times at conventions and at one point I had a copy of it.
I have not done a scene by scene comparison, but just looking at it quickly. the original B&W/Color version of The Cage and the restored full color show very little differences. The DVD release has the original in 29.790 fps and the restored version in 23.976 fps. In places the hybrid runs faster and in others the restored runs faster. There are also noticeable frame drops in the hybrid during the B&W sequences.
There are some small bits of dialogue missing, which survive in some recordings of the full 16mm print from Roddenberry. It’s all in sections where edits were made in the Menagerie, which makes it understandable why they were excluded in that initial hybrid cut and never restored. I think the rest of it concerns soundtrack changes; music from ‘The Man Trap’ is looped into many sections, again casualties of The Menagerie.