Just finished it, and was not impressed, despite having a Skaven army and collecting a Lizardmen one, and having read tons of fluff and lore behind each (loving them). It did have some redeeming qualities, such as the lizardmen's point of view and the Thanquol parts.
POSSIBLE SPOILERS!!
- The story was kind of lame and pointless. The motives for the Skaven are weak at best, the parts with the humans were dull.
- Most of the other characters (read; Not Thanquol) were just meh... Adalwolf is stereotypical and boring, same goes for Sommerhaus, and hilltrude is just ridiculously out of place.
- It feels like the writer had the Lizardmen army book in front of him and then thought "well, I HAVE to introduce EVERY single one of these critters" and so he does. It's like he's counting on the mere fact that a particular chapter has a terradon in it will appease the fanboys enough so that they dont notice that he described its cry as "warbling" 3 times or such. Really? Was that necessary?
All in all I think the writing is below average, but then again, I might be jaded after treats such as Lies of Locke Lamora, The First Law, ASoIaF and the name of the wind.