Ok, so here’s the thing.
I really, really liked this movie. A lot. And that’s pretty rare, for me. I tend to see flaws, I expect a lot, I’m easily detached and not easily manipulated. But The Prestige really worked for me in a lot of ways.
And yet - oh, why must there be an “and yet”? - I can’t really say I LOVED it, because it bothers me quite a bit that the “magic” of the plot (pardon the pun) depends on the audience accepting a totally fabricated “scientific fact” within the otherwise realistic world of the story. It’s not fantasy - this isn’t a fantastic world. It’s just a (wonderful, weird, and admittedly very satisfying) TOTALLY MADE-UP THING. And, shades of Erica, I think that’s cheating. Because the movie doesn’t follow any of the other conventions of fantasy - it doesn’t create its own world within which we might be persuaded to accept the veracity of this fantastical element. It just fabricates a thing that can’t, and doesn’t, exist in our world in order to create a surprising reveal at the end. And that just doesn’t work for me, intellectually or artistically.
It kind of works for me aesthetically, which is why I still really enjoyed the movie. :-)