Saw was good, Saw II wasn't bad, and then they just kept going downhill. Each one kept going back and injecting itself into the previous movies and just made a mess of things.
Saw V was a confusing mess (a lot of that due to two of the main guys looking almost exactly alike) and I imagine Saw VI will have any more confusion so that it can try to cram all the events that happen in Saw VI so they interweave with the events of Saw I-V (what's the called again, metastory? Something like that).
I'm not really expecting anything from it though I'll Netflix it eventually.