AFAIK, only difference is Signature series is cheaper. However, looked at Holly E Ordway's review at
DVDTalk & found some differences:
| I did a scene-to-scene comparison of the Signature Series release and the earlier release from Lions Gate, and as far as my eye can detect, the transfer is identical. |
| The original Spanish soundtrack is presented in Dolby 5.1, and appears to be identical in audio quality to that of the earlier release. |
| Two featurettes are included. The first is an eight-minute behind-the-scenes featurette that offers interviews with the director and various members of the cast and crew; it's reasonably interesting, and it's new to the Signature Series DVD. Rather oddly, though, it replaces a longer, fifteen-minute behind-the-scenes featurette that was present on the earlier release. |
| The only new material on the Signature Series DVD is a different (but shorter) making-of featurette, and the storyboards and photo gallery. |
Tim