I am very impressed with this Omnibus. The characters are interesting, the combat is described with just the right amount of detail, and the pacing of the stories is just as good.
The biggest criticism I can throw at the first Omnibus is that there isn't much character development in the first novel, as it is more a collection of short, intense stories than a full-fledged novel. However, if you stick with it you'll find that the characters themselves, as well as their supporting cast, grow steadily from the second novel and forward into the following novels.
I'd recommend this Omnibus to anyone who likes the fantasy genre and, particularly, anyone who likes well described combat and richly described settings. I suppose that if you prefer incredibly deep prose, you may be slightly turned off by the topical approach these novels take, but I can't imagine too many people feeling that way.