Quick quick summary: the original book in the sequence, "Ender's Game", is much better.
"Xenocide" does proceed to answer some questions asked at the end of "Speaker For The Dead", but whilst it was nice to do that, the way they were answered was not so great. "Xenocide" is quite a heavy book to get through. It feels complex for complexity's sake, labouring to make the points the author wants to make rather than letter them make themselves. For example, Card strays into the argument about Predestination versus Free-Will - one that Theologians have been arguing over for centuries. Fortunately he doesn't go in far enough to get lost in there, but the lightness of the treatment plus the fact it was mentioned at all made me wonder about the other topics he's burdened the book with.
Don't mistake me: it wasn't a difficult book to read, in quite a few spots it was a page-turner and I got to the end easily. But it was a bit ho-hum on balance. The characterisations relied an awful lot on what the reader remembered from "The Speaker For The Dead". That also tells me that the plot was too involved.
It also falls victim to the desire to explain everything (and he's far from the only author to do this). The genetic tampering on Path is a good example. The way the Descolada works is another. The philotes is a third. In fact, that's almost the worst thing wrong with this novel: the fact that philotic communication is explained. And that leads directly to the very obvious deux ex machina at the end surrounding the FTL travel. Oh, Card works hard to try to make it not that, but I think he painted himself into a corner. It was not a satisfying ending.
That said, there were some good things. The conversations between Ender and The Hive Queen were a good example of utterly alien thinking meeting human thinking and were actually rather well done. One exchange had them both going round and round in circles simply trying to communicate. There were a few other scenes where Path culture brushed up against Lusitania culture and they were well done, too.
But, really, this was a noticeable distance from his best work.
Wade.