Combat Doctrines will need to be strategically used to align with what your army is doing that turn, but in all cases, giving your army an additional -1 AP is huge. Armor is practically paper thin with this rule and that helps us kill stuff. But let's be honest here, we are going to start seeing a LOT of marine armies in tournaments now so you're going to have to prepare for this. Camo cloaks, invulnerable saves, LOS blocking terrain, and movement shenanigans are going to be critical going forward. One downside (if you can call it that) is that it forces us to stay pure non-specialty Space Marines or we lose access to the Combat Doctrines. However, I think this is a great change as it discourages soup lists. I think this is a great move by GW and I hope its one implemented with more codices going forward. With that out of the way, let's look at some units that I believe will have some cool interactions with our CT's or some big winners in the new codex.
Drop Pods. Dude. Seriously? Alpha Strike is back. As of the new codex release, drop pods the tactical reserves rules. That means you can drop these in your opponent's face again on turn one for a huge first turn strike. If you're savvy, you can get some pretty good units right into your opponent's line and destroy it. Then your opponent will be on the defensive the whole rest of the game. While you might consider these dropped units expendable, if you bring in a Company Ancient, you'll at least get a chance for shooting again with your units before they die. There are lots of tactical applications for this, even if you're only taking a couple drop pods.
I feel I have to mention one of the understated, but important big winners of the new codex: Grav Cannons. These guys got a pretty hefty buff with the new codex with a points adjustment (20 points a pop) and the new stratagem Gravitic Amplification. A decent gun got cheaper and now you have a 1 CP stratagem to reroll wounds/damage. That's pretty huge. Combo this with drop pods and you can easily wipe units off the board. Devastator Centurians also got a huge buff here, but they are harder to set up for a strike. They require a ride, so that is a huge point need for your list.
The next unit that I'm pretty high on is the new retooled Chaplains. The way they are setup, you have the option to buff your shooting units, your assault units, or the Chaplain himself. That is pretty good. There are a ton of different options for this guy, but I like the "Slaplain" setup. For a mere 90 points and 2 CP (unless you make him your Warlord), you can get a close combat monster that strikes at strength 8 and damage 4. Plenty of juice to take on vehicles or monsters.
I am also pretty enthralled with the Invictus Tactical Warsuit. This thing is scouting dreadnought. Are you kidding me? This is probably one of my favorite units in the new book. I keep it with the basic flamer, which by the way, has a 12" range. Utilize Concealed Positions and you'll potentially be in range of the enemy on the first turn. That is a scary proposition for them, as you're putting out a butt ton of firepower AND have a newly improved CT that will help it get into combat. Or if you have the 2nd turn, it'll eat tons of shots from your opponent and that will be okay, since you're only paying 131 points for each. They won't want to charge you either, since you're automatically hitting them in overwatch with that Incendium cannon. Awesome unit.
Eliminators received a big buff with the new codex, which makes you much more likely to take Headhunter points in ITC format. Now rocking Str 5 rifles and some fun new rules for falling back from a charge, you'll see these become a huge thorn in your opponent's side. Especially if they are sitting in cover. You can also take them as durable anti-tank hunters, but don't expect them to take down a Knight.
Reiver squads got a decent points decrease, so combining Shock Assault with these guys finally does something worthwhile. A basic 5-man squad with grav-chutes generate 21 close combat attacks. This is not even counting their pistols or special grenades. They are cheap harassment units that can definitely hold their own in close combat; even better if you're in the Assault Doctrine. This is a great way to ensure you are putting enough units on the board to take advantage of our CT.
Intercessor squads have to be talked about here. Not only do they have a bigger body than our Crusader squads, plus the benefits of extra attacks...they have dedicated stratagems that can either buff their shooting to prodigious levels or make them pretty beefy in close combat. But let's be realistic here...shooting is where they really shine, so let's not waste them in close combat. Are they good enough to spam? I don't think so. Scouts squads are too cheap to drop completely. But Intercessors will start seeing TONS of play. And for good reason. Bolt Rifles are going to be king.
Finally, one of the biggest winners in the book is indirect fire. Not only is the Suppression Fire stratagem in the book, which will allow a Whirlwind or Thunderfire Cannon to be able to fire twice...you start the game in the Devastator Doctrine, which gives an additional -1 AP to all of your shots. Indirect fire can devastate your opponent's army from behind LOS blocking terrain. There is so many units out there now that can use it to great effect. Pound your opponent first turn with artillery, close in with bolt weaponry, and finish them off in close combat. Sounds like a plan.
So how about you guys? Anything that really strikes your fancy? Coming up in the next few days is my first list, which I am rather happy with. Its my first rendition of the "Peek-a-Boo!" list. :D