Disclaimers before we begin: this is all based on one game in an odd format with no reference to points or power balancing. That said, these are impressions based on an actual game with full access to the rules and datasheets so I guess it might be of use to someone.
The format of the game was simple: come to GW on games night with an HQ, a Troops unit and “something cool”. There were four of us: myself with my Flesh Tearers (I didn't get my Black Templars, for that is what they were finished on time), Matt with some Traitor Guard (using standard AM rules), and two people who I shall refer to as Rugby Shirt and Baseball Cap out of respect for privacy and not knowing Rugby Shirt's name who had Khorne Daemons and Tau Empire respectively.
We divided into pairs: me with a Librarian, Tactical Squad and Death Company Dreadnought and Baseball Cap with Tau Commander, Fire Warriors and a Crisis Battlesuit Bodyguard Team vs. Matt with Command Squad, Veteran Squad and Rough Riders and Rugby Shirt with Daemon Prince, Bloodletters and Bloodcrushers. No scenario, standard twelve inch deployment, fight!
So, first eighth impressions:
Dreadnoughts are a lot more survivable. Mine ended up in combat with the Daemon Prince and Bloodletters. It died but it survived two turns and got the Daemon Prince down to one wound before it fell. The fragility of walkers has been a problem for a while and this has been very effectively addressed.
On that subject, the ability of small arms fire to wound anything came into use with the Veterans chipping off a wound from the Dreadnought. It took an entire squad (and Matt muffing his rolls for his meltaguns) but they took off a wound.
Multiple wound and multiple damage weapons got a rollout on all sides. The fact that multiple damage doesn't carry over between models balances it out nicely. Firing my meltagun at Matt's Veteran Squad was pretty ineffective as I was basically wasting two thirds of its power sniping off one model.
The ability to use pistols in combat is an idea I'm surprised hasn't been included before. It makes dedicated assault squads more effective for what they do and actually enhances Tactical Squads rather nicely, making them the all-rounders they were always meant to be.
Flamers are better. On paper they have much the same range they always did but, like other ranged weapons, if even a part of the target unit is in range you now get to fire with full effect. Obviously, they hit automatically which is more than enough compensation for losing the templates.
Supporting charges, or whatever the actual term is: great idea. It always seemed strange to me that a unit could be standing a few feet away from their comrades being minced and do nothing for a few minutes. Nice and fluffy idea, good mechanic that makes the opponent put extra consideration into considering their charges.
Chargers attacking first: unalloyed good, no problems there even if we kept forgetting that all chargers had to attack before we moved on to the alternate activation. Just a thing to get used to.
And, finally, as far as Johnny Number Blindness here is concerned, a To Wound chart that can be explained in simple sentences is worth its weight in gold.
I am still not entirely convinced by the AoS-style leadership. None of us lost more than a couple of wounds to it at a time, the single D6 and generally high leadership on our units meant it was quite forgiving. Get back to me once I've had reason to test it out with my Orks.
Falling back from combat... well, I imagine it has more utility in bigger games. In our game all it really did, when we came to think about it, was deprive my Tactical Squad of using their pistols in the next turn. Probably the best use of the rule is to open enemy units up for a firing solution from more effective ranged weapons.
No firing arcs is ultimately good though I do miss the mechanic of picking enemy models off from the front of a unit backwards. Its probably for the best and means you don't get sergeants and such hiding in the middle of the unit which just looks... well, crap.
That said, the ability to effectively “hide” characters from all enemy fire unless they're the closest target is perhaps not the most logical idea (there would be times when you as a commander would want to target the enemy general) but the Rule Of Cool applies. You just want to get your general into combat with the enemy general and this facilitates that.
The Bad (or, The Will Take Getting Used To)
I think the relative ease of firing off psychic powers might be a bit OP. Again, am impression that will need a few larger and more balanced games, preferably ones where I don't have the only psyker on the table, to sort out whether I'm right or not.
Not getting extra attacks for charging isn't a problem but the brain has had years to program its cost/benefit analysis around the idea of charging as a force multiplier that it will take some adjustment. It has its bright side: it means combat units will be prioritised for combat instead of just charging everything in that's in range. Its a good mechanic that means units will be used more frequently in line with their background purpose but, again, a little mental adjustment is in order.
Overall, I was impressed. The game flows a lot more organically than I've ever seen it, there was very little rulebook flitting and no significant unbalances came up from four pretty diverse armies.
Quiet confidence is beginning to transform into moderately loud confidence.