Today I'm going to be covering the 2nd least expensive of the aligned choices, in the form of Khorne Berzerkers, and Kharn. I don't really have much else to say, so I'm just going to get straight on with it.
Base, Khorne Berzerkers are very nearly 20pts, so almost 50% more expensive than a standard Chaos Marine, and the difference is that they have +1 weapon skill, Fearless, Furious Charge, and dual close combat weapons and Mark of Khorne base. So just of what they get they don't look too bad, so moving into the upgrades.
Firstly, you can take up to 20 of them, and then fire a sizeable points cost upgrade any model may take a Chainaxe. This will change 2 things. Firstly, they will look really cool, secondly, they will be AP4. Now, anything with an armour save of 4 or less is something that you're going to be taking down anyway, so if you're looking for purely gameplay strength don't take them.
2 Khorne Berzerkers can also get Plasma Pistols, for almost the cost of a whole other Berzerker, or 5 Chainaxes. Each. Backing away slowly.
The Berzerker Champion can then do all of the normal Champion things. Gift of mutation. No. Artefacts, better on a Chaos Lord, Melta Bombs. Ok, maybe.
Now, for the same as a Plasma Pistol you can get an Icon of Wrath, and if I was certain that I wanted to take Berzerkers then I would take this. What it does is let you re-roll your charge distance as though you had fleet, which is really useful as the last thing that you want is your Khorne Berzerkers to get shot at.
Finally, the Khorne Berzerkers can take Veterans of the Long War, which I would take, rounding off their points cost nicely and Hatred is always useful in combat.
However, this all sounds good but I still don't like them. There are a couple of reasons for this. Firstly, they don't have an AP value attack, and they don't have access to a decent one. Therefore, they have to rely on weight of attacks in order to do some damage to MEQs. They have 2 attacks normally, double that on the charge. So assuming 10, 40 attacks hitting on 3s (assuming that they all survive overwatch). 27 hits. Wounding on 3s for Furious Charge. 17 wounds. 6 Dead marines, although if they are marines you're getting Hatred too I suppose. But still, that's not that impressive a tally.
Now let's think about how to make them effective. Well first you need to be able to get them into combat safely, they're only marines after all and they're likely to have a big target on their head. So you'll need to give them a transport. A Rhino won't do as it's too flimsy and you can't assault out of it. So you need to take a Land Raider, that's getting expensive.
Ok, so now you're getting into combat, but the Land Raider only has a transport capacity of 10, so you're not going to get enough attacks out to kill a whole squad, and if you do, the rest of the army will gun you down no problem. I can't take more Berzerkers to get more attacks out because then I won't fit into the Land Raider, so I'll just drop the squad down to 9 and put Kharn in there as the 10th (segwaying like a pro).
Kharn is a character that is designed to do one thing, and that is to kill stuff. His weapon skill and ballistic skill match Lucius, but he has +1 strength base, and Furious Charge. He hates everything, has a 4+ invuln and Plasma Pistol, and a strong number of attacks. However, what distinguishes him from a beatstick Lord are his other 2 rules. His first is his Axe, Gorechild. It essentially is a Power Axe, but with a few modifications. Firstly, he strikes at normal initiate, secondly, it's armourbane, and thirdly, it hits on 2s. Pretty brutal.
However, every time Kharn doesn't hit, he hits a friendly model in his unit instead, so a hefty cost for every miss. So, do you leave Kharn in the squad? The alternative is to take him out and have them charge separate targets, but then Krak Missile will instant kill him with only a 4+ save in their way. So, you leave him in the squad for fear of losing him. He is the same points cost as Huron, although he is immune to force weapons, and denies the witch on a 2+. However, I would be cautious with this, as Kharn with 9 Khorne Berzerkers in a Land Raider will set you back almost 600pts.
My honest verdict here is that it's not worth it.
So is it worth making Khorne Berzerkers troops? Well in making things troops you're either doing it because you want something to score or because you want to run an army based around a unit. Do Khorne Berzerkers score better than standard Marines? Well they're slightly more durable because of Fearless, but on a point for point basis having more Marines is probably more durable, and they can shoot. Do you want to build a competitive army around Khorne Berzerkers? No. Never mind then.
If Kharn had Eternal Warrior, I may consider taking him without the Berzerkers in a squad of Chaos Marines or something, but because GW appears to be cutting back on that kind of thing I probably wouldn't go for him. He could be ok, this is just standard internet punditry, he's still a beatstick, I'd just try to keep him out of sight of S8+.