I’m breaking this review in half. This part will be purely on the rules section. I’ll read the fluff section when I get a little more time.
Everybody I’ve spoken to is buzzing about the new flyer rules. I think I might actually see a Tyranid Harpy in this rule-set. I predict a lot more flying models being used in this set of rules. Related to that I think the reliance on template weapons may be shifted in some armies in favour of more shots. The Hydra with an AA mount could be one of the best value guard units in the codex now.
One of the things that slowed the game down and caused consternation for me in 5th edition was the wound allocation rules. In 6th edition these seem to have been made clearer and more concicse. With any luck this will speed up the game a bit and be more realistic (no more removing the gaunt at the other end of a 30 model line).
Special rules and weapon qualities. First off I love the idea that melee weapons now have an AP. A Power Sword no longer cuts through Termies like a scythe through a pestilent boil but will ignore Power Armour. A Power Fist will still smash through any armour without pause. If you can remember that little section on special abilities in 5th edition you will be surprised by the masses of them in this book. It looks like they have centralized as many of the abilities as possible so that different codices will use the same wording for the same rules. This should aid in fairness between armies. There are new versions of the errata for every codex up on the website. Helpfully the sections that are to do with the new rules are in Magenta so that they are easy to pick out.
There are generic rules that different model types all get. Infantry/bikes/jetbikes/jump/monstrous creature/flying monstrous creature. I could go on but you probably get the idea. Again there appears to be a feeling that more of the rules should be in the main rule book. I think the next codex release will have very few unique rules and instead refer to various special rules.
Psychic powers are worth a mention as well. For each codex you have the option of keeping your usual choice of powers or swapping any powers (including ones you buy) for one from a school that is open to your army. School I hear you say. There are five schools of powers and each codex has access to three of them. Some of these powers are just plain horrible.
Generally I feel that to start with games are going to take a LOT longer, but moving forward things are going to be a lot quicker. Especially as most of the special rules will be from the rule book and not from a codex that you haven’t laid eyes on in several years. I look forward to having some proper battles using the new rules.
Overall I think that the new rules look very good but only time will tell.