The more I read the new Warriors of Chaos, the more I think that the designer has done a good job.
Generally the two biggest complaints from army owners is the repricing of Marauders - especially the pay per model for Mark of Khorne - and the changes to Skullcrushers. In both cases I think the changes were warranted - 50+ units of Khorne Marauders with Flails were too cheap - and the Skullcrushers were the best Monstrous Cavalry in the game. The repointing of the Skullcrushers hasn't been all one way - the extra wound and changes to Jugger offset by the reduction in T fully justify the 78 point cost.
So what do I like about the book?
First and foremost, the variety. Only the Orc & Goblin book has more unit choices. This means that there is an incredible opportunity to build lists, look for different synergies etc.
Following on from this, there is now competition in all slots. For example the Lord slot has three contenders with the elevation of the Daemon Prince. The Troops slot has variety too. Now you can have vanguarding Dogs, Marauder spam, Core Chariots as well as the mainstay with infantry. Initially I though Chariots were the new black, now I'm leaning to a more combined arms approach. However what you take has to fit with the rest of your list. So I think this will mean more variety.
The Special slot again creates conundrums - Knights, Dragon Ogres, Chimeras, Chosen (with or without Warshrine). There are a lot of choices to make and opportunities (read builds) to explore. Even the Rare slot is busy. I like Hellcannons but can I fit them and Skullcrushers in? What about the Shaggoth - increase in stats and 50 point decrease?
Real real variety.
I haven't even begun to scratch the surface in regards to Lores but Nurgle in particular with its buffs and damage spells looks a good Lore and even if you mark your users you now have access to a battle college lore.
If I was a WoC general I wouldn't be moaning. Instead I'd be rejoicing at what a great and varied book GW have delivered. Yeah, sure it's different but all books are. Look at the longevity you have in comparison to say the variety in the Ogre book (ref NZTC lists). Here you have a multitude of viable alternatives rather than predominantly one single build.