I personally think some of the units have had their abilities reduced. Some have had them enhanced. Others have had their prices reduced to a manageable level. Some units are just silly, and I see no reason why they introduced them. as we already have the defiler and dreadnought/hellbrute.
Some of the new rule and upgrades are good, but you have to pay for them.
I personally would have liked them to allow you to theme your army to represent a post heresy Legion. Night Lords, Alpha Legion, do not get any form of representation with these rules. Iron warriors and Word Bearers get HQs, but they do not allow for night vision skill (night lords), or tank hunter skill (iron warriors). I can still theme an army - sort of with noise marines, thousand sons, plague marines or berserkers, but these mean other armies will generally look the same. The only way to make a unit into a classic - we have been fighting the long fight is to give them veterans of the long war upgrade.
I love obliterators now, but would have loved for them to have a max of 5 models in the unit. The same with mutilators.
I would love to have been able to design a night lords army with extra raptors (which should be allowed to count as scoring), then have all models with night vision, and chosen, get outflank/infiltrate.
An alpha legion character would have allowed for all CSMs and chosen to get infiltrate and shroud, and allow certain troops to outflank.
Well the codex is out now, and we can not change it, so what can you do now if you want to theme your army and make it work as close to your chosen legions historical abilities and tactics?
I am pretty much set as I have an Emperor's Children army, but my Night Lords army is going to be just another CSM army with no marks of chaos at all.
I suppose I will have to re-design all my lists I have typed up, while I am waiting for Army Builder to bring out a new update for the CSM codex.
I will have to have a full read of the codex before I make my mind up, but all in all, they have not completely screwed it it, but it is not want I and a lot of older chaos players would have wanted. Rather than add in a lot of weird new war machines, I wanted a new hover/flying transport, some equipment and unit price decreases, and some of the units maximum unit size increased not decreased. At 15 points possessed is still not worth it.
I suppose many will like somethings, and hate other things. The codex is better than the last one, but it could have been way better without being too over powered. Now it just has somethings nerfed, others improved, but at cost, and somethings just so over powered that I will probably not use them. Especially when they cost so much for the new models in Australia.
I do not have a utter hatred for Phil Kelly for what he has done with this codex like I did with Gav and Alessio for what they did with the last one. I know many still hate Matt Ward for his Grey Knights codex or some of the Fluff it introduced. I have not yet have had a chance to decide how I feel about this codex.
Most things are evened out for their price, and to make them super over powered, you have to pay a lot more points in upgrades. Thankfully standard weapons are now a bit cheaper. I would have like to see flamers and missile launchers as free upgrades for standard CSM squads, but that is just my opinion.
I still can not believe I had to pay $83.00 for the codex though.