When I was in 7th and 8th grade I read every single Poirot book I could get my hands on. I loved trying to figure out who the murderer was before Poirot did. But the problem with some of Agatha Christie's later books was she didn't actually present all the clues to solve the murder. It was frustrating because I felt lied to; like there'd been a secret I hadn't been party to, which made me look like an idiot when the truth came out. "Well, everyone knew Dave had an evil twin brother who'd been locked in an insane asylum 30 years ago." Gee, how could I have guessed that?
This was the same problem with The Illusionist. The movie, in essence, is about the rekindling of a childhood romance. That sounds boring, but with the added wonder of it having a Magician, it sounded like it was going to be a fun film. The acting in it is great, I can't fault that. I can't even fault the story, it's got some good twists and interesting characters. What I fault is that the magic tricks are done with CGI. Now that may seem like a weird fault in this day and age, but this is a period movie. By doing the magic tricks with today's technology, the director denied the audience the chance to question how the trick was done and even whether or not it was a trick.
This may seem pithy when you have a good plot and characters, but the movie is a "Who-dunnit?" and because the illusions were actually CGI, the audience wasn't presented with the clues properly. This made the revelation at the end feel cheapened because you couldn't have predicted it on mere facts, only on cliché plot archetypes.
And yes, having a revelation and a twist at the end is becoming completely cliché with movies involving magicians.
I think most people will enjoy the film, but for me, part of the enjoyment was lost because it wasn't staying true to its period, and missed out on getting a really interesting insight into what it meant to be an illusionist in that era.