The Dreadclaw and You!
Among the many delightful toys that Imperial Armour 13 brought, none is more influential to the Chaos Space Marine army than the Dreadclaw. Other units in the book are good, and might even be taken more frequently, but only the Dreadclaw has the power to totally change the way you construct an army.
What is the Dreadclaw?
Don't let the name fool you, the Dreadclaw is an armoured flying assault vehicle, not just a Drop Pod. Half of them arrive turn 1, in hover mode, allowing them the ability to move 18" after landing, as well as increase it's own survivability though jinking. Units have the option of deploying after landing, but can also choose to stay inside their AV12 shell, until the following turn when they can launch an assault.
You can purchase the Dreadclaw as a Dedicated Transport for all of the Helbrute/Dreadnought variants, Chaos Space Marine and Chaos Chosen squads, or you can take them as single Fast Attack choice and transport whatever you please. There are two unfortunate downsides to the Dreadclaw though, it's fairly expensive, nearly the price of 3 Space Marine Drop Pods, and it has a 1/6 chance of eating a random model inside. If you have a Warpsmith, Sorcerer with Malefic Daemonology, or Abaddon inside the pod however, you can choose to have a model eaten or not, and select the unfortunate victim.
When you take Dreadclaws, remember that they are expensive, you will not be running 5-7 of them like a regular Space Marine army, nor should you. 1-3 is probably the most ideal number, remembering that half of them will be showing up on turn 1. Be sure that whatever you put inside of them can take advantage of being on the board right away, or at the very least, should be ready to charge into combat on turn 2.
That's the Dreadclaw in a nut shell, now lets talk about some units that you could put inside and why you should or shouldn't.
Chaos Space Marines
First up are the basic troops in the army, with a squad of 10 being able to take 2 special weapons plus a combi-weapon, as well as pistol/ccw if they so choose. They can take a mark and/or icons to increase their combat capabilities. They do have a problem with leadership however, which is bad news for a combat unit. Without the Icon of Vengeance, or a Fearless character, they do have the risk of losing a round of combat and being wiped out. Generally, I consider the Dreadclaw to be too expensive to transport Chaos Space Marines, just due to their unreliability. The only redeeming value of transporting Chaos Space Marines is that the Dreadclaw then becomes Objective Secured, which can be pretty interesting. If I were to transport them however, it would almost certainly be a squad with 2 meltaguns and a combi-melta, trying to take out an armoured target.
I think that Chaos Chosen can potentially make the most use of a Dreadclaw. Being able to take a whopping 5 special weapons, plus a combi-weapon, a squad of 6 chosen can really cause some serious damage to a vehicle in an alpha strike. They're also quite effective in combat, each having with an extra attack, as well as pistol and close combat weapon. Due to their advantages in assault, I'd only consider taking squads with Meltaguns or Flamers, since you can't assault after firing plasma guns. If you're taking a full squad of meltas, it'll be up to your discretion (and where you land) if you get out right away and shoot something, or if you stay inside a turn before you get out so that you can pop a transport and charge the squad inside. Chosen really do have the opportunity to use all of the advantages of a Dreadclaw, you can alpha-strike, or you can stay inside, you can deliver a bunch of special weapons, and they can fight in assault as well. If you play Black Legion, then you also have the added bonus of them being Objective Secured!
Helbrutes, Contemptors, Dreadnoughts, etc.
I wont go into too much here, right off the bat having a 1/6 chance to eat the model inside just means I can't even consider transporting one of these vehicles. If you want deep striking walkers, take the Mayhem Pack instead.
Finally, there is a way to deliver Possessed directly into combat! Unfortunately, possessed are still quite expensive, but taking a full unit of 10 of them with Mark of Khorne or Mark of Slaanesh, could really end up being a devastating punch. If you take them as Crimson Slaughter, they'll also be objective secured for extra laughs. The downside naturally is their cost, Possessed are still quite over priced, and 10 with marks, an icon and a pod is going to run you over 400 points.
Another unit meant for combat without any reliable delivery method, Mutilators hit like a truck when they ever make it into a fight. A fully upgraded squad of them comes in under 200 points, and is quite survivable, they do suffer from Leadership issues like the Chaos Marines, but are far less likely to lose a round of combat. Putting them in a Dread Claw definitely gives them a means to make it into combat, where before they would deep strike and just hang out in the open, hoping to survive a round. Their low model count and expensive cost per model does make being eaten a real threat though. If you take them with a Warpsmith, you create quite a nice little deathstar, nobody will get eaten, but you're again back up to about 400 points like the Possessed, though far more effective.
Unfortunately, I think that putting terminators in a pod is still not that spectacular or interesting, they could deep strike before, and they're outclassed by Mutilators in combat, or by Chosen and Havocs for alpha striking meltaguns.
I think that this is a pretty obvious combination, the ability to get Berserkers into combat safely might be one of the greatest things Khorne could have asked for. They're naturally fearless, so you wont need to worry about about them losing combat, and they're devastating on a charge, so losing that combat wasn't likely anyhow. They're moderately expensive, but nothing near the price of Possessed, a full squad of 10 with champion, power weapon and Icon of Wrath, in a Drop Pod is still well under 350 points. They do lack special weapons to shoot with, so you'll probably always remain inside your pod after you land, then the next turn dish out a devastating charge. I'll have to experiment with this a bit to see if the Berserkers are finally viable.
Quite the opposite of the Khorne Berserkers, transporting a squad of Thousand Sons is quite expensive, but it can end up delivering a ton of AP3 firepower to a vulnerable location. Like the Berserkers, I'll be experimenting with this to see if it works, but the idea of a fairly resilient unit that can devastate a marine squad being delivered into the enemy backfield is intriguing at the very least.
Plague Marines are never a bad choice, though I'm afraid that now that they don't re-roll to wound against T4, that they're outclassed (as they should be) by Berserkers in close combat. Plague Marines are also an expensive source of special weapons when compared to Chosen, and since their Dreadclaw would be taking up a Fast Attack choices, I'm thinking that Rhinos will still be the transport of choice for them.
The servants of Slaanesh are often overlooked as close combat units, though it's a shame to do so. They are only about 1 point per model more than a loyalist space marine, but come with I5 and Fearless. Their special weaponry doesn't really benefit assaulting, except on the champion who can get an amazing Ap3 flamer. You could potentially also put in a lord with a Burning Brand of Skalathrax and deliver 2 AP3 flamers deep in the enemy line, before assaulting the following turn. Their Icon gives them Feel No Pain, so noise marines can also be surprisingly resilient. As far as taking the most advantage of a Dreadclaw goes, I'm not too sure, I think that more specialized units might still be better off with them instead.
Like Chosen on a budget, you can get 4 special weapons and a combi-weapon on a squad of 5 Havocs. Though they wont have the close-combat advantages as the Chosen, you will save about 25 points on a squad of 5, and if you're just using it as a suicide melta delivery system, then you may as well save the points. The obvious downside is that it means your Havoc Squad is taking up 2 slots in your army, but that's not all doom and gloom if you make use of Allied Detachments, or a second CAD.