I just finished reading Wolves of the Calla, the 5th Dark Tower book by Stephen King. I have to say this was probably one of the best books in the series. The lead up to the battle was very well done, and the further exploration of Roland's world was very interesting.
The only thing I don't like about the DT series is how King is tieing every book to it. In the past, King would make sly, yet small references to his other books. This was fun for the avid King reader. Now it seems like every thing is tied to the Tower, which, makes sense if you accept his view of the Universe, but as a reader gets a bit tiring. I was disappointed to see the sequel to the Talisman, Black House, written as a DT tie-in. Even though the Talisman had a very simular premis (multiple planes of existence), I felt the tie in to DT was forced and just not necessary.