Effects.
Is it just me, or did the effects get a lot worse in Season 2? I mean, season one's effects weren't the greatest, but they were pretty good, the fact they were shooting a lot of it on green screen didn't really cross my mind till the end of the first season,i was too engrossed in the story. Ive started watching season 2 and wow, the effects are not only really obviously CG, it's bad CG. It looks cheap and rushed, the mouth effects anyway. I don't hate CGI, just so long as it's used convincingly and has the work put into it(Example: http://incravenegospera.wordpress.com/2012/06/01/some-thoughts-on-cgi- prosthetics-and-sets/). I understand it's TV and there would be a limited effects budget, but why not write something different? Also you could tell that stuff in the Vatican City was done in front of a green screen, but then again, how could they afford to go to the real place, so it's kind of forgivable.
Other than that, I really like the show. =) It's entertaining, an interesting idea, a little convoluted in terms of it's overall season arcs but no more so than Torchwood: Miracle Day.
HEEEEERES JOHNNY!