I just finished reading it. I enjoyed it. Eldar still do some stupid things, but there's no imperium and the tyranid are even more xeno's than eldar so they get to win for once.
If you've read the iyanden book you already know the story though because a lot of it is covered in there.
the formations are cool too actually and if I knew anyone that owned tyranids I would try to do some of the apoc scenarios
altogether my favorite war zone book, but i don't like imperial stuff so that's not hard >.>