SPOILERS AHEAD. If you are caught up on the TV Show, no biggie.
Soooo, I actually was only half way done with Book 4, not 5, and finished it today. The reason 4 & 5 seem soooooo long is they are parallel stories. Book 5 isn't a continuation. Book 4 was mostly about what was going on in the South (Except for the Jon Snow/Castle Black story) and Book 5 is mostly about the North and Danyerys. GRRM wanted to make one book but decided it was way too much so he just wrote them parallel. I just finished chapter 1 of Book 5. So far, the TV Show has mostly been from Book 4.
GRRM has been very vocal about how this season mostly mimics the book but there are LOTS of differences. The Margarey/Loras story is very different but the Cersei part as it relates to those two is similar if not identical. Jamie doesn't go to Dorne to rescue Myrcella--Cersei sends someone else. Jamie goes North to take Riverrun. The Sansa Stark story is completely new on the TV series. She has a pretty boring existence in book 4 as Robin Arryn's caretaker. Ramsay Bolton married a girl named Jeyne who is pretending to be Arya Stark. She is treated as viciously as Sansa. Brienne's story is different as is Jorah and Tyrion.
Both are equally good and I am glad that I am reading and watching both. I'm trying to keep current in reading with the TV Show but it is getting difficult. These books are LOOOOOONNNNNGGGGG. Book 5 is 1500 pages.
And, I could care less about gratuitous nudity. haha. There hasn't been as much of it this season now that the Sparrows are in full force in Kings Landing.