Havoc
Havocs are the Chaos Space Marines' equivalent of Devastators. Like their loyalist counterparts, these guys drag the heavy weapons into battle, laying out copious amounts of fire to support their brethren. Havocs can equip the basic heavy bolter/missile launcher/lascannon options that Devastators can, though you won't be seeing any plasma cannons, multi-meltas, or grav-cannons on your spiky guys. Unlike loyalist marines, Havocs still have access to autocannons that can be lugged around by a single Marine, which they are more than happy to bring along with them. They also like to stick big-ass bayonets on their guns, just in case the opportunity to stab something with an autocannon, heavy bolter or lascannon presents itself. Unfortunately, not only is their resin kit absolutely awful, as one of the units at the absolute bottom of GW's priority list they're also nigh impossible to get a hold of. Convert some Devastators instead and you'll be much happier. However the new Shadowspear box set is out soon and your beloved chaos boyz will be getting a new box set soon as well with some fancy new gubbinz.
On the Tabletop
Havocs clock in at 13 points each, just like their loyalist counterparts. Outfitted with a Bolter, Bolt Pistol, Frag Grenades and Krak Grenades, up to four Havocs may trade in their Bolters for either a Special or a Heavy Weapon. The list is more limited than the loyalist one, but it does grant access to a neat little list of guns. The three special weapons are listed below. Note that the squad's Aspiring Champion can take a combi-weapon of the same type for only 2 points more, netting you that one extra shot.
- Flamers are, well, flamers. 1d6 auto-hits is nice, especially when you use several against a large blob of infantry. Cheap too: for 47 points you can equip the entire squad plus Champion with five.
- Plasma Guns really shine in the new edition. Rapid Fire 1 with S7 AP-3 will really ruin the day of any MEQs you come across, but multi-wound TEQs can prove to be a bit of a problem. Risking death from the supercharged shot is risky and not that rewarding. Put the squad into a transport, drive them within 12" of the targets and unload your 10 shots for massive damage. 67 points for a full loadout.
- Meltaguns are meant to melt tanks. S8 AP-4 DD6 will really ruin a tank's day, especially when you shoot it five times. Transports are required to get within the 6" for the damage reroll. Pretty expensive at 87 for the full five shots.
Next are the Heavy Weapons. The Champion can't take one of these, but they come with the bonus of being usable at long range.
- Heavy Bolters are your bog standard anti-infantry weapon guns. The full set nets you 12 shots at S5 AP-1, so don't try and use them against something too large. Do note that most Heavy Bolters you'll have will be on tanks, who get -1 to hit often because they move around a lot. Only a fraction of the cost of the other guns, so if you need them this is the place to go.
- Autocannons have become less useful against one of their primary targets in 8th edition: light and medium tanks. Sure, the S7 still has a decent chance to cause damage, but the AP-1 will really hamper their effectiveness against good saves so the D2 won't be able to do its thing. Still, a full squad gets 8 shots with the things, so you can look at getting at least a few wounds in. Monsters with high Toughness but average saves (aka most Tyranid gribblies) are often better picks, so choose your targets wisely.
- Missile Launchers are expensive (100 for a set), but they make up for it in versatility. Frag missiles let you take huge chunks out of blobs, while the second shot is a poor man's Lascannon. This means that you'll always have the proper response to a target, and at a decent range to boot.
- Lascannons carry potent tank popping abilities. They render armor saves a formality and can deal crippling damage against tanks in the most average of circumstances. You'll pay through the nose for this right though, so keep them safe.
- Reaper Chaincannons are the new kid on the block with Games Workshop's new Chaos expansion. Sort of. It's literally just a bigger, beefier, and spikier Proteus pattern Rotor Cannon from the Heresy, but hey, it sure as hell gets the job done. This is a pretty good way of BRRRTing your way through most MEQs and lower, with 8 shots at strength 5 and AP-1 but it does only have a 24" range.
Havocs have access to Chaos Icons, but aside form the Icon of Vengeance these are circumstantial at best. They can also pick one of the Legion Traits. The Renegade, World Eaters, Emperor's Children and Night Lords ones are not all that useful. The Word Bearers grant a re-roll on Leadership, which is handy to make sure you don't lose yet another of your big guns. The Black Legion one is useful only if you're equipping them with Plasma Guns. No, where they really shine is with the Iron Warriors and Alpha Legion ones. The Iron Warriors let you ignore cover bonuses and gives rerolls to wound against buildings. The former is incredibly useful against anything in cover, while the latter ability is useful against any fortifications your opponent brings to bear, as long as you bring the big guns. The Alpha Legion's ability gives a -1 to hit when targeting your unit from more than 12" away. This is spectacular: Havocs are fragile enough as is, so being more difficult to hit is all but mandatory to stay alive.
Speaking of staying alive, Havocs have access to five additional meatshields for 65 additional points. This is not very cheap, but it does wonders to keep them alive. They cannot bring any special guns to the table, so you have to choose between outfitting them with either Bolters or with chainswords. Bolters let you hit enemies within 24" of the unit without sacrificing firepower, while chainswords provide an extra attack. While this does not seem very meaty, it can prove a nasty surprise for any enemies that seek to assault the Havocs to keep them out of the fight. The champion can hand over his bolter and bolt pistol (so no three pistols like the Devastator sergeant!) to pick two from the pistols and melee weapons list, or take a combi-weapon. Unless you are planning to take special weapons, doing so is not really worth the price. Sure, a power weapon/plasma pistol combo is fun to play with, but you won't really getting a lot of mileage out of them. Plus, they don't help with the champion's main job: being a meatshield.
Before you outfit your Havocs with special weapons, consider the following: Chosen. Only 3 points more expensive a pop, Chosen have superior Leadership and one additional attack. As a more melee-oriented unit the Chosen can hold their own in a fight, plus they profit more from whatever Icon they might be carrying. On top of that, not only can they pick four special weapons, they can also pick combi-weapons. For only two points more their gun is also a Bolter, and the -1 to hit penalty for double fire does not matter when using Flamers. On top of those four guns, the Champion can pick any gun he wants and an additional model can pick a regular special weapon on top of that. Suddenly having a unit of Night Lord Chosen pop out of a transport, set you on fire and charging to frightening effect only to force an already difficult Morale roll at a negative modifier is not good news and something that Havocs just can't compete with.
Power Ratings
When it comes to Power Ratings the Chosen are a flat-out better choice when it comes to special weapons. They cost the same 7 points that the Havocs do, but they've got a superior profile. As for the Havocs themselves, the expensive array of lascannons or missile launchers is suddenly a lot less expensive when it costs a fixed amount of power. Upgrading your Champion just in case is a lot more useful as well since it's no longer wasted on a meatshield. And speaking of those: upgrading to 10 Havocs so you have 5 extra meat shields is only 3 points. This is immensely useful at this point, and the free Icon makes you a bit better as well. Then park them someplace safe and watch them lay down the smackdown upon enemy forces.
And then the Vigilus Campaign happened
Eventually, GeeDubs agreed that the Havocs were shit, and so Havocs were massively revamped during the Vigilus Campaign. First off, the bad - they had a small points increase, everyone but the Champion can no longer carry Special Weapons, and the size of the unit can no longer be increased with fodder Marines. However, Havocs were made to distinguish themselves from their Chosen compatriots in other ways. For starters, they were boosted to Toughness 5. They also inherited the ability to ignore the to hit modifier for moving and shooting with Heavy Weapons, meaning they're no longer sitting still all game waiting to be shot at - and since all they can carry now are Heavy weapons, it's something they needed to stay viable. In short, there are now legitimate reasons to take Havocs over Chosen if you want some cheap big guns. Oh, and they got a new gun in the form of the aforementioned Reaper Chaincannon. Because it apparently took the Traitor Legions 10,000 years to come up with the idea to upgrade their old Rotor Cannons to shoot Heavy Bolter size bullets.