It isn't confusing at all. What are you talking about?I really liked it. The traps are pretty insane. It's kind of confusing and I 'SAW' it with someone who hadnt seen the first 3 so it was REALLY confusing to her.
But it gives you a good look at Tobin (John/Jigsaw) and you understand him a lot more, actually the movie makes you sympathize with him IMO.
The script writing is so freaking clever. You have to pay attention as mentioned above. This one is for the fans.