"Person of Interest" keeps moving, shifting the pieces in unexpected but somewhat reasonable ways, keeping itself interesting: they don't just get a number and rescue a person, episode after episode. No - they find themselves facing off against different groups who want to control the machine, or destroy it, and different crime families arise - and some of those simply don't behave as expected. A lot of TV shows do things too absurd for their audience to accept - it's called "jumping the shark" for a reason - but "PoI" has mostly managed to keep its twists within the realm of reason given the context of the show. This was an interesting season for me - I found the twists alternatively annoying and intriguing, and in the end enjoyed it rather more than I expected to.
Jim Caviezel's acting continues to be poor - but that's okay, because he's surrounded by a bunch of other poor actors: Michael Emerson, Taraji P. Henson, and Kevin Chapman. Even Enrico Colantoni, who is a thoroughly capable character actor, is underused and poorly managed in his few appearances as "Elias." But better a consistent level of acting than one standout making the others look bad ... And their handling of technology - from Harold Finch's magical hacking skills in which he can break into anything in seconds (unless the story calls for him not to), and the phone "forced pairing," among others - continues to be ludicrously silly. But let it slide - it's a fun show.