I just rewatched this episode last night (along with Demon). A really good epiosde imho for the fact it doesn't let the audience in on them being the copies until after B'elanna dies. There's the relief that the real crew's fine but also the tragedy that the copy crew are dying. Janeway's insistence on getting back to Earth and not returning to Demon is frustrating - this has been her main purpose which has kept her going all these years, she can't easily switch to a different way of thinking. Seeing the copy crew die at the end without anyone knowing about them was tragic but it's one of the few episodes showing things don't always work out in the end.
A few inconsistencies in the episode as some others have mentioned - how could they breathe non-Demon air when that was previously a problem (perhaps they adapted)? How could they spend all that time not knowing they were replicas considering the EMH extracted... silver blood (?) from Tom and Harry in Demon (again, maybe these were more perfect replicas)? How could they have memories when just cloned from DNA as mentioned in Demon (possibly some sci-fi science excuse)? How did they replicate the ship AND the EMH (some silver blood covertly traveled around Voy in Demon taking notes)? When Tuvok is looking at logs it shows the encounter at Demon from Voy's perspective (copy crew must have faked logs... because they wanted to forget the truth??)? How come the copy crew never went to a planet Voy had been to - not one! - and met people who said "Hey, you're back!"? How come copy crew are nearly back to Demon and encounter Voy which would mean Voy had hardly made any progress? And probably loads more...
Not that I care about these little things... overall, an enjoyable - and memorable! - episode.
A few inconsistencies in the episode as some others have mentioned - how could they breathe non-Demon air when that was previously a problem (perhaps they adapted)? How could they spend all that time not knowing they were replicas considering the EMH extracted... silver blood (?) from Tom and Harry in Demon (again, maybe these were more perfect replicas)? How could they have memories when just cloned from DNA as mentioned in Demon (possibly some sci-fi science excuse)? How did they replicate the ship AND the EMH (some silver blood covertly traveled around Voy in Demon taking notes)? When Tuvok is looking at logs it shows the encounter at Demon from Voy's perspective (copy crew must have faked logs... because they wanted to forget the truth??)? How come the copy crew never went to a planet Voy had been to - not one! - and met people who said "Hey, you're back!"? How come copy crew are nearly back to Demon and encounter Voy which would mean Voy had hardly made any progress? And probably loads more...
Not that I care about these little things... overall, an enjoyable - and memorable! - episode.