This is probably the most gorgeous CG animated movie and along with Avatar the most visually stunning 3D movie to date. The colors are beautiful, the motion capture generally convincing, the mix of cartoon styling with photorealism just right, and Spielberg's characteristically great camerawork is even better without a physical set holding it down.
Unfortunately the dialog is merely serviceable (especially for Tintin, whose every line is a comic book speech bubble suggesting what will transpire next), the gags are rarely funny, the constant, seemingly random action scenes become tiresome and the story is mostly void of both intrigue and emotion.
The greatest asset of the movie - the lack of physical restraints - is also at times a weakness, when the film occasionally goes to an almost Looney Tunes extreme of physics-defying action that just doesn't mesh with the pseudo-realistic art and animation.
For those fine with a meaningless animated action romp or willing to appreciate a film purely on an aesthetic level it's probably still worth watching. If that is the case, then by all means take the opportunity to watch it in the cinema and in 3D.