Very disappointed. I'm a huge fan of the original, and thought the sequel had its merits. But the third one suffered from sequelitis. Bigger does not mean better.
The gore and twists were pumped up to the max (I've been a horror movie fanatic for over twenty years and found this to be one of the goriest films I've seen).
But it was all so contrived and gratuitous. Everything in the first film made perfect sense, and the gore and twists were there to drive the plot on. Here it felt as though the writers were more focussed on how clever they could be with the gore and the twist rather than the plot. And at I found it really hard to care about any of the characters, other than the first two from the second film.
All the best ideas from the original felt shoehorned and therefore lost their power.