I'm a fan of the first Saw movie. I think it had the (psychological )goriness of great movies like Se7en and nice twists. Sure there were weaker things in it; its realism was to be taken like the average horror movie: not. But at least it hinted towards it, making it easy to swallow.
This movie however, fails miserably. May i note here that this movie is a desperate rip-off of the instant Canadian classic Cube. I'm not sure what the intention was with this movie; it seems that it was confined to simply do what hadn't been done in the first. As if one more crazy trap would make it worth the effort. To me, quite the opposite happened. Although i counted two creative traps, i counted more than i wanted which were aggravatingly idiotic.
I find it very annoying when the villain has an intelligence far superior than God himself. I also find it very boring when characters do stupid things, which are not explained, or, worse, they just do it for the sake of doing stupid things. Those movies were already done in the 70's with more remakes and sequels of even worse quality.
Where Saw I tried to be inventive, this movie is your standard completely flopping sequel. Where the first one had characters and plot twists worth developing, this movie is just a bad mix of blood, violence and stupidity.
I give it a 3, because the start wasn't that bad and the actors do try their best. But in the end, the plot fails, ending is weak, characters are not developed, the villain is a joke and the open ending is purely for commercial purposes. I guess in the end this is your standard Hollywood BS production.