I used to have the double-length feature on VHS back in the day, and I used to watch it quite often because they're brilliant episodes. I had this tape before I saw part one by itself, and remember being quite shocked at the amazing cliffhanger that i missed out on. I may be remembering wrong, but I think the musical cue at the end of part one is a bit truncated in the edited-together version. There was definitely no cut to black.
I do remember either Dr. Crusher's wig changed, or the lighting did, between dramatic moments. Must have been the shock.