It's nice to see the author tackling something a little different from his bread and butter recluce works.
Having read the review on the back of the book first (a big mistake), I did think it was going to be decidedly formulaic naff sci fi. Luckily, whoever wrote the bumph hadn't read the book...
Tackling "ethics" could have bogged the book down in slow moving moralising, but Modesitt manages to inject enough life, action and interest into the plot that it drags you on at a good pace. Well thought out politics and people give this a lot more depth than just one book would indicate on the subject.
If you're after deep political discussions, good dialogue, finding innovative ways to blow ships up, a hint of a tint of romance, genetic manipulation, revenge and retribution, sensible religious discussion then buy it. Closest in style to Ian Banks' books than much else out there.