My last review has all the links to the reviews that I have written for the other books in the series if you are interested. All Together Dead was trying my patience with these books, and as youthfulzombie pointed out in the comments of that review, the TV series is better than the books. That is mostly true, overall I believe that the show is better, but there are certain parts that I prefer in the books, mostly parts of dialogue and certain story lines in the show (hotshot for one) that are so much different on the show and not necessarily better.
Either way, how I look at it is this. I am sort of obsessed with True Blood, I read recaps of episodes and scan the forums when I am bored. To me the books are another way to get a bit of the characters that I have come to love through the HBO series. I will keep on reading them as long as they keep putting them out, same as how I will keep watching the show as long as it is on. Well, unless either one drops in quality by a significant amount.