I have mixed feelings about the movies.
as a little background I should explain: I'm an independent filmmaker. Writing and direction currently, I'm aiming to get into Columbia's film school in New York so my views may come off as a little pretentious, its only because I analyze the movie deeper than just the story. Such as execution, lighting, angle, geometry, acting, duration etc.
The concept of the series' is absolutely genius. The traps are brilliant and they do them tastefully, instead of "OMGEEEE COME LOOK AT THIS GUY GET ATTACKED BY TEH' SHARK. OMG THATS SO GROSS. OMG OMG OMG OMG GORRRREEE. *drool*" that people like Tarantino made Eli Roth do in hostel 1 (I'm very glad Eli got his control back in Hostel 2)
The acting is generally sub-par, but it's easily ignorable. The lighting is stereotypical horror movie lighting, which isn't very creative, and you'd expect a higher level of creativity for such a revolutionary series.
But what really gets me is the way its normally shot in grainy high contrast. It reeks of teenager uses photoshop for the first time, making pictures of themselves all grainy and inverting the colors. Its very amateur.
But overall I love the series. I love the fact that they actually DEVELOP Jigsaw and a character and as a human being. I don't know about you, but in the last two movies I've actually started to feel for him as a person, and actually like him as being an intellect and trying to do something good for the world even though it is extremely warped.
And, to help clarify, I believe they've gotten the green-light to go up to 7-8 in the series.