I love this film!
I have not read the books so only have the finished film (that I imported on region 4 DVD) to judge.
Much has been made of the fact Hayao Miyazaki did not direct this himself, leading to some approaching this astounding and visually beautiful directorial first from his son Goro with a sense they were going to be cheated of a worthwhile movie experience.
They were a bit harsh!!
I do agree with the recent review in Neo in some respects.
Really, you'd best trust your own tastes when it comes to the offering from Ghibli. As long as you don't go into the film looking to compare father and son you will be fine and should enjoy the film.
However, it's not perfect by any means. Some backgrounds are a little less detailed (but still perfectly suitable for the film), the pacing is slower than previous Ghibli works leaving those less patient bewildered as to what they are watching and of course certain character designs and indeed entire scenes remind you of Miyazaki Senior.
After seeing the film I had a sudden desire to hunt out my Ghibli collection and watch Nausicaa, Laputa: Castle in the Sky and Princess Mononoke in particular.
If you can ignore these very minor flaws, the film itself is actually pretty good and does stand up to repeat viewing.
Btw, Timothy Dalton is excellent as Sparrowhawk, so do check out both the English and original Japanese tracks on the DVD.
I for one am looking forward to future films from Goro Miyazaki. He may not be quite in the same league as his father (yet), but his work shows great promise.