In the battle of dueling Victorian magicians, I'd definitely give the nod to The Prestige over The Illusionist. In particular, I thought The Prestige did a better job of keeping things somewhat in the realm of the possible, if not plausible. Each of the two magicians here went to basically superhuman lengths to create the ultimate trick, and one of them involved a science-fiction leap forward (courtesy of a nearly unrecognizable David Bowie as Nikola Tesla). But it was a gimmick that was at least plausible in the film's universe, while Eisenhiem's nearly holographic phantoms at the end of The Illusionist just seemed beyond what was possible technically in that film's universe.
Which is not to say there were no shortcomings here. The movie seemed to go to great lengths to keep its big reveal at the end unmentioned - it was only shown for a split-second before a smash cut to black and the credits - but it was pretty clear what was going on and just what lengths Angier had decided to go to in order to claim his "victory" over Borden. The opening of the film had the opposite problem - like several of Christopher Nolan's other films, this one jumped back and forth between several timelines before converging at the end. Here, it led to some confusion, simply because I hadn't gotten all of the characters' situations straight at that time. Less confusing than Momento, to be sure, but also not confusing in a good way.
Still, I like these kind of films, with two characters going at it to one-up each other all the way to the end, and this one was very well done. And with Bale, Jackman, Caine and Johansson, this was certainly a good cast. All in all, a very enjoyable film. Four stars.