I will preface my comments by saying that I hate the Governor character and storyline. I hate every single thing about it. It has nearly ruined the series. On top of feeling like something the author introduced so he could shoe-horn more overt drama and action into what had actually become a thoughtful character-driven narrative, it also feels too convenient that there'd be someone like that, in a community like that, so ridiculously close to the prison. Everything about the Governor and his community would've been a better fit for the early issues when Rick & co. were wandering around looking for a place to stay -- it could have prompted a lot of character development and exploration of human nature in that context, since after settling into the prison Rick & co. would be living in constant fear of the Governor or another like-minded individual attacking them. But as it stands it just feels like the sort of thing a Hollywood producer might have demanded be introduced into a film he felt wouldn't reach a wide enough demographic.
That said, this volume does an excellent job of establishing how and why the Governor is still alive and why he was able to rally so many people to attack the prison compound so many times. When he showed up at the end of the previous volume I felt like it was a cop-out, something I might have expected from a Batman or Superman villain, but which didn't fit in the context of "The Walking Dead". Kirkman, however, does an excellent job of establishing his survival, in addition to the timing and motivation for the attack. As much as I hate the Governor and what his character's introduction brought to this series, this volume handles it well.
All that said, this is one of the most brutal installments in the series and certainly one of the most depressing. It is not for the faint of heart, and the loss of SO MANY major characters, including a horrible decapitation and an act of infanticide... Well, the death of the Governor at the end can't make up for that. I may keep reading the series, but it's only because I bought the next two volumes before reading this one. I'm finding it harder and harder to stay emotionally attached to any of the characters -- why bother when Kirkman is just going to contrive newer, more horrific ways for them to die? By the end of this volume, almost everyone who makes the series worth reading is dead, except for the increasingly-uninteresting Rick Grimes & son and the annoying magic-ninja Michonne (anytime she's involved my suspension of disbelief is shattered). Every single character aside from those three is turning into the zombie/rifle-fodder one associates with teen horror films, and when I stop caring about the characters...when i stop feeling the need to keep track of their names and their personalities...well, it may soon be time to stop reading the series all together. I can get the same nonsense from any B-movie about zombies.