So I picked up the codex today and have had a looksy. My initial thoughts are this, its a well balanced codex that has the ability to deal with most threats on the 40k table. Nothing is particularly indestructible, but reasonably tough and priced. It can take care of air, armor, and infantry, and has reliable cover reducing options, though lacking ignores cover outright. The CC units are not bad, though will def require playtesting to get their use right. Overall, its a very solid army that has a lot of tools at its disposal.
There are some choices though that come out as subpar. First off lets talk about the plasma caliver, its 18" assault 3, with usual plasma profile. Its also double the cost of a plasma gun. At 30 pts, its just such a hard choice to take this. Its cost is extremely high and it still has gets hot. Granted, its assault 3, but its half the cost of a ranger squad, two cost 5pts short of one, and three gets you half way to a second squad. Compared to the other special weapon options, having a hard time with this one. Not bad, but its cost prohibitive, best in pairs at most in a small squad. I have a hard time sinking that many pts into this gun.
The arquebus is expensive as well, at 25, but its a lot more versatile. It has a 60" range for one, plus being an ap3 armorbane sniper weapon, it has a lot of targets it can hurt. Being sniper it counts as s4 against vehicles, with armorbane giving it 2d6 for pen. Against T3 or less opponents, its not as effective as galvanic rifles, but anything T4 and better and it loses no effectiveness while having a nice anti armor punch. This works for the price, as a min squad of rangers with two of these can hit infantry and light vehicles, and the range compliments each other well.
The arc rifle though is the real winner, at 15 pts you have a 24" S6 Ap5 rapid fire, haywire gun. Its just all around good, and get in close and a few of these will decimate just about any armor around. This is a go too weapon for vanguard, its not bad against infantry, and it just kills vehicles no matter how tough they are. It has a good range too, and if you get within 12" it will do a lot of damage. I like it and this will work well and will be seen a lot.
Doctrina imperatives were the big unknowns and they are quite nice. You have six options, each being one use and affecting every unit with the special rule. No leadership tests are required, you just choose which one, if any, at the beginning of your movement phase, and last till your next turn. Basically they are broken into shooting and close combat. One is +1 to BS with no negatives, one is +2 with -1 to WS, and the last is +3 BS and -2 to WS. The CC ones are the same, but with BS and WS modifiers reversed. Its just solid, no tests to make, you have a one use rule you can apply where it really matters. The BS ones will be used up for sure, but don't count out the WS ones, it can turn their CC units into very hard to hit ones in CC when used at the right time.
Relics are ok. The first is cheap at 5pts, and relatively situational in that you can reroll mysterious objectives with the bearer. Its cheap but only useful if you play with those objectives. In short, its not going to be seen a ton. The next one is the phase taser at 15pts, and its not bad. It is +2 S melee weapon with taser (to hit of 6 causes 2 additional hits) and inter dimensional electrocution, which causes a model that suffers one or more wounds to take an initiative test, and if failed it is removed. Its solid and well priced compared to other skitarii melee weapons.
The omniscient mask is next at 20, it grants the zealot rule. This is good, essentially giving fearless plus bonus in first round of combat. Good for boosting one of the cc units, but otherwise not top choice. The Pater Radium is the same price as above (20), it causes enemy units locked in combat after I step 1 to take a toughness test, which if failed causes D6 wounds with no armor saves. Not bad on a vanguard alpha.
The Phosphoenix is a 6" S5 AP2 pistol with lumigen (reduce cover by 1) poisoned 3+, with phosphex which basically means a to hit causes 3 hits. At 25pts, its not a bad pistol, which is basically a 3 shot if it hits. Overall a good choice for your warlord, not necessary though. Last is the Skull of elder nikola at 25pts. Its a one use, where you roll a number of d6 equal to turn number and enemy vehicles within that number of inches suffer as S1 haywire hit. Its neat and not bad, expect to see it occasionally.
The big thing is that the only restriction on relics is that they can only be one of each. There is no restriction on stacking relics though so you can put the Taser and Phosphoenix on a guy if you want. Between special wargear and relics, you can build an decent warlord out of an alpha that can survive and be a decent killer. He will be better than an IG company commander or Scion commander kitted out, and have a similar cost to the IG CC, and more than scion commander (though you don't have much options in that regard).
The warlord traits are not bad, they do make your warlord better. One grants eternal warrior, next master crafted to one non relic weapon, next reroll feel no pain for warlord, next gives shrouded (great), next reroll failed morale pinning and fear tests, and last lets warlords unit fire at BS 4 for overwatch. No stinkers and you get to reroll for detachment, so not a bad choice and a contender with strategic traits. Shrouded is the def winner, but others are not bad.
The dunecrawlers are definitely the cornerstone of the book. These can do whatever you want, anti infantry, anti armor, anti air. Really these will be seen a lot. The icarus array is just deadly and a pair will still not take a huge chunk. Neutron lasers will murder armor (48" S10 AP1 blast concusive). And the basic weapon will do great for a line breaker playstyle.
Overall, this is a great book, and its going to be a bit to figure out all the synergies, but really its good. The cc units may not seem stand out, but I have a feeling that they will be of use once it gets figured out. This will be an army that can stand on its own and will be a go to ally choice for imperial armies.
More to follow, but these are my initial thoughts
GG