So, the Get Smart movie is wonderful, really. They've totally reinvented Maxwell Smart as someone who, while lacking the slick, amoral affect of a movie secret agent, can shoot, fight and dance competently with almost unbelievable listening comprehension in several languages. The story, really, is about a morbidly obese intelligence analyst who gets himself in shape to be a secret agent with the mission of bringing human understanding into espionage work. It's really very inspiring.
The movie falls down when it tries to reattach to Get Smart, the TV show. The bits with the cone of silence and Agent 13 in a tree are funny, but distract a little from the story. I found particularly jarring the catch phrase "missed [it] by that much." I'll explain, if you're not familiar with the TV show.
Often, Max's genitals would get shot at or nearly punctured by something or other. There would be a moment of tension, Max would gingerly check his groin, and report back wtih "Missed by that much," holding up his thumb and index finger. That last bit's important, because in the movie, he uses the catch phrase twice, but doesn't hold up his fingers. "That' refers to nothing. The movie's trying to elevate a little -- they're not penis jokes -- but you simply can't say, "Missed it by that much" without holding up your thumb and index finger. It's jarring to the audience.
So, I'd recommend the film, but only if you're willing to forgive the failing of wanting to refer to the original beloved series a little too much.