^^^Biggest missed opportunity in the films was NOT to have the D in FC. If you thought the Borg were scary, just imagine them assimilating the civilians, including children and pets. The D was a miniature Earth with all the aspects of a human (and some alien) community onboard. The E were a solely military crew of volunteers. Assimilating soldiers into drones isn't as powerful a demonstration of what the Borg are going to do as the assimilation of families would have been.
Oh absolutely.Not to mention the ship itself. I can imagine seeing the familiar-and-comfortable Enterprise D sets being slowly converted into Borg alcoves would have had far more emotional resonance with the audience than the same thing happening to a ship we've only known for five minutes. The audience wouldn't have the same emotional connection with the 1701-E as they would have done with her predecessor in that situation.
I agree that it would have been just as horrifying to the audience to see the ship we watched on TV all those years being slowly lost to the Borg. But being as they actually had a budget and time to do the film, I'd hope they would have done it right. The proper thing to do would have been having the Enterprise separate the saucer section the way it was supposed to and we would have spent the rest of the film seeing the battle section be assimilated.