I've been very slowly loosing interest in the show this season. I don't think it is Shaw so much as I just feel like the writing hasn't been as effective this season. The tone of the series feels off; it has kind of lost the dark realism that informed seasons one and two and it (to me) feels a little too camp or melodramatic at times this year. It isn't a drastic change as the basic situations are the same, but the execution feels subtly altered and not in a good way.
I felt this way too, but further back in season 2.
I didn't really watch season 1 in its original first-run broadcast. I started watching PoI sometime during the first part of season 2. I was randomly channel surfing and noticed Michael Emerson was on the show, which sorta kept my attention at first. (I remember Emerson previously in LOST). Though at the time in early season 2, I thought the episodes were rather bland and generic.
Around that time I also found the season 1 bluray set heavily discounted (circa black friday last year), which I then watched through over a weekend. I liked season 1 a lot more than the then-current season 2 episodes I was previously watching. In comparison, season 2 seemed a lot "brighter" and more "relaxed" than season 1. (For lack of a better description).
Except for the episodes with Shahi, Acker, and Parrise, I thought the rest of season 2 seemed like a generic procedural show.
In the case of season 3, so far I've found the first several episodes kinda on the generic side with the same "brightness" and "relaxedness" as season 2, except for the parts with Acker.