The first three are definitely the best so far, this one goes on and on. It is still enjoyable and if you loved the first set, you'll still enjoy this one. A little more action and a little less description is what's needed.
Frankly, I believe there comes a point when complexity overwhelms the story. Most readers don't have time to read it all at once and when they pick it up at a later time, they forget some of the important details that were immeresed in so much other none important stuff.
Just one readers opinion.
**A book I would also recommend is The Unsuspecting Mage by Brian S. Pratt. This, the first installment of The Morcyth Saga is a great beginning for a new author. Battles, magic, gods, secret passages and intrigue, all the elements of a classic epic fantasy! Any fantasy reader will enjoy it. Also, it gets right to the story and isn't nearly as 'descriptive'.