Jedi Knight, while still not as good as Soldier for the Empire, is a definte improvement over Rebel Agent.
For most of the book, the writing is back to Dietz' standard from the first one; fast paced but clear and understandable. Unofortunately, the last 20 or so pages would have been better expanded to 40. Again, in those last 20 pages, there are no less than three Jedi battles, a flashback to a huge historical battle, and the ending all stuffed in there. While it works, it would have been better expanded a little.
Also, many of the film characters are out of character. Although they aren't in the book much, Han doesn't sound like Han, and Luke's remembrance of Yoda doesn't sound right (Yoda's talking about subatomic particles or something). Also, this is kind of hard to place in relationship to Rebel Agent, as here Leia is Leia Organa Solo, and in Rebel Agent she is just Leia Organa, but there isn't really enough time between them for either version of her wedding to have occured.
Dorman's art, while not as beautiful as Williams's, is up to his usual standards. Occasionally the people look kind of funky, but all the landscapes, backgrounds and ships are exceptional as usual.
This book really explores much more deeply the workings and motivations of the Dark Jedi, especially Yun but including Sariss and Jerec. It shows clearly how and why the dark side of the Force is so tempting.
The action is still very good, but it was annoying seeing a lightsaber fight described in fencing terms. "She made a head cut, and he responded with Parry 5." Just doesn't sound right.
Still, its a much better book than Rebel Agent and a good conclusion to the trilogy. If you liked either of the others, buy this one.