I made it through only a few episodes of the first year before giving up on it, though I peripherally experienced some later ones too. James Marsters in the second year seemed to give it some additional promise, but since I regard the entire premise of Torchwood as highly flawed (to put it mildly), it wasn't nearly enough to get me to care.
I have seen Children of Earth, mainly because I was in the room on my computer while it was being watched. It did seem to be better at first, but I found the ending so vile and repulsive that my anger at the previous years was nothing in comparison. Seriously, that was the only thing they could come up with? What the hell ever.
This was the moment that my view of Russell T Davies changed from being a flawed but still promising writer, and instead plunged off the deep end into wangsty nonsense; and his severe mishandling of the end of his run on Doctor Who only cemented that perception. Not that I worship Steven Moffat like a lot of people do, either: he's absolutely brilliant with scifi ideas and timey wimey stuff, but from his often-ridiculous portrayal of women (and various comments he's made in interviews) it's obvious that he's rather sexist, which probably explains why many of his female characters are caricatures with no real depth. When he doesn't let this get in the way, it becomes less of a problem. (However, there is no force in this world that will ever make me cease to despise the ludicrously horrible Mary Sue that is River Song.)