Trying to rope in 11 characters, making them funny and tying in a great robbery is no small achievement. That said, as such the plot of thieving the Casino is not very original or well laid out. Who cares?
There are so many other aspects of the movie that can be enjoyed. The characters are funny, and atleast some of us well introduced to us. Brad Pitt and the others do an okay job. You really cannot blame them, as they either have to just look good or sound and be funny.
In spite of all this, the movie presents a lot of cool, and runs along at a mild place with the laughs appropriately placed.
The climax is filled with expected surprises and is well tied in the movie. Having watched it hours before Oceans 12, I can say the sequel was predicted even while the original was being made and hence you are left with this expectant excitement.
As a final word, if you are looking for a hilarious movie or a great work of art, forget it. In its own slow pace, the movie is an intrigue for people who just want to kick it in and laugh. Enjoy this before you watch the sequel.