In my opinion, The Dwarves started off really well. In a few chapters, Heitz manages to explore an interesting realm, Girdlegard. The early characters are introduced against a nice backdrop, and as a reader you start to care for them.
Halfway through however, the book lost me. In a matter of a few pages, all the main characters die and new ones are introduced at a rampant speed (thus failing to get interesting). Moreover, when Tungdil, the main character, finally realises his lifelong dream (getting reconnected with his kinsmen), the author takes very little time to describe it.
The book then continued to disappoint me with a fairly straightforward and pretty predictable story. The subplots were all too feeble attempts to colour the characters. Of course, if you want to describe a great LotR-alike quest in less than 300 pages, you are bound to miss ample opportunities to make a story truly remarkable.
Nevertheless, I did enjoy the book and already started in the sequel (War of the Dwarves), hoping that it will be better.