I thought Syndrome was a lousy villain, to be honest. It really didn't detract from the movie for me, but he either needed to be more over-the-top-melodramatic or a lot more menacing. The greatest shame would have been being beat by an opponent with no style.
And they broke the cardinal rule of comics - don't kill the bad guy. Where would Batman be if the Joker actually died?
I loved the movie though - I don't want my picking of nits to detract from that simple fact. I would think it would fall colose to the "must see" category for people of our ilk.