This is the 3rd time my Saw loving persona has sat through this, I thought I'd write a review from the perspective of both a Saw fan and someone who simultaneously appreciates film and the future of horror cinema.
Jigsaw fails mainly on trying to cater to two sets of fans, for one satisfying the long time fans and to cater to a new audience. Taking the by-the-books formula the Saw movies have used since Saw IV where a game takes place while cops do some things but simultaneously referencing none of the previous games and characters established and loved by most fans, creating a fresh slate in a soft-reboot style.
Strangely for a franchise known for torture porn (though I will defend the orignal to my death) there is an extreme lack of campy gore effects which I'd never thought I'd say I miss, but the movie misses a lot of the fun Saw III - Saw 3D had (yes, even the one with pink blood).
As for the trademark twist that every movie ends on the finale for Jigsaw ends up towards the bottom on the ranking, recycling the same "someone else was helping" twist that has happened (effectively) in Saw II, Saw IV and (not so effectively) Saw VI and Saw 3D, despite the producers saying they went through hundreds of scripts.
The reason I'm giving this a higher rating than Saw V and 3D relies on technical aspects, no more do the scenes have a gross green filter covering the movie and house some of the best camerawork seen in a Saw movie. When Tobin Bell eventually showed up the movie elevated as always, since he seems to be the last cast member who gives a shit about this franchise (because christ, most of the lead males in this were as wooden as Costas Mandylor). I don't even need to mention Charlie Clousers score as it's always too good for these movies.
Part of me appreciates their vision to target Saw to a new audience on a clean slate, but on the 8th film in the series the only people that care are the fans. I miss the campy gore, the overcomplicated writing and answering questions established by other movies because we seemed have forgotten to do that, and as Saw will continue as a Halloween tradition I hope they take these notes on board.
All that being said, I still had a blast finally seeing a Saw movie in a cinema and I'd maybe rate a star higher if I just went on my enjoyment.