Confidence is a cute movie that won't subvert or rise above your genre expectations.
I think this movie could have been really great if it had simply done more. the twists should have been twistier. The sex could be sexier. The quips could be quippier. The Style could have been... stylier?
Its biggest failing is that the stakes aren't high and even if they were you don't care about the characters. You know they'll succeed, no ones gonna die and they'll happily explain how they did it to the audience and drive away grinning in a convertible but not into the sunset. its a noir film they just drive off into the night.
But it doesn't disappoint. This sort of thing is hard to do well and i always appreciate the effort. just don't expect too much, its film by the numbers crime/grifter movie edition.