It is - of course - tradition for horror franchises to contrive some way to return the killer and thus allow there to be additional films and thus, more money - what makes the Saw franchise a little different is that the third film ends with him being pretty unambigiously killed and the FOURTH one shows him in the process of being autopsied (and no, he's not jumping up like Michael Myers or Jason). So... it's somewhat impressive that having died in Saw III, his machinations are still afoot and as elaborate and nigh infallible as ever in Saw VI.

There ISN'T really much to seperate this film from the others... there is actually something of a narrative thread here, which is to say - this film is a BIG author filibuster about health care in the USA and the role of the insurance companies in screwing people over on their health insurance... all of which takes something of a back seat to Jigsaw basically exceeding a BATMAN level of planning, forethought and prediction.

It's not hard to see why the writers want to keep Tobin Bell around, he's pretty much the only character who has been in every film and he's a fine actor and really, the most iconic thing about the entire film series is the creepy puppet with Tobin Bell doing the Jigsaw voice - that and the twist at the end of the film.

This is pretty much what anyone who has seen a Saw film would expect, which for most means this probably won't be worth going to the cinema for.