Whoops, I forgot to write about the Forge World Knights even though the Index has been available for download for a while now. My bad. Anyway, let's get to it!
We shall first begin with the Acastus Knight Asterius, which has a whooping 30 wounds and Toughness 13 and a 2+ save. He has the usual volkite culverins with devastating wounds, a Karacnos mortar battery that's 2+ anti-infantry and ignores cover. But everyone's interested in the twin conversion beam cannons, which are twin-linked, 48" range, 3 attacks each, Strength 16 AP -2 Damage 6, and has Sustained Hits D3. The new conversion rule simply gives you Critical Hits on a 4+ when the target is more than 24" away, which means you'll be getting D3 extra hits for each hit roll of a 4+. The Knight Asterius has no Bondsman abilities, but instead improves his Strength and Damage of his attacks against vehicles by 1, and 2 if you're shooting fortifications. He's the most expensive Knight available at 730 points.
The Acastus Knight Porphyrion is almost the same, but with a Helios Defense missiles instead of a Karacnos mortar battery, which you can swap for an Ironstorm rocket pod that's better than the Questoris version because it's D6+6 hits, and the autocannons that you can swap for lascannons. The twin magma lascannons are twin-linked (which means reroll wound rolls), Strength 18, AP-4, Damage D6+6. They are D6 attacks each, with blast. He gets Lethal Hits for ranged weapons if he stays still, but no Bondsman abilities. He's almost 100 points cheaper at 645 points, which is bewildering. But okay. Is there something I'm missing?
The Cerastus Knight Lancer is awesome now, and Cerastus Knights have 25 wounds now. The Knight Lancer has a 4++ invulnerable save. That's it. Not just in close combat, but from ranged attacks as well. Cool! His shock lance isn't good at shooting, with Strength 6 AP0, so don't expect it to do much against Space Marines and Marine equivalents. But you want him in melee, where he'll dish out 5 attacks at Strength 20 AP -3 Damage 8 or 10 attacks at Strength 10 AP -2 Damage 3, both at WS2+. Wow. Just wow. He has a Bondsman ability that allows Armigers to advance and charge, and his own bonus is using Tank Shock Stratagems for free every time he charges, even if you've already used it, which means you can deal a bunch of mortal wounds every time you charge. Damn, son. He's pricey, though, at 430 points, putting him above all the Questoris and Cerastus chassis, but just below the Dominus (and Acastus, obviously).
The Cerastus Knight Castigator is a budget Knight Warden that has a twin-linked bolt cannon that fires 18 Strength 6 AP-2 shots. Wow. He gives Armigers Sustained Hits 1 and a bonus AP -1 for their ranged weapons too, instead of -1 Damage, while he himself will debuff a non-vehicle and non-monster enemy target, giving them a -1 to shoot or fight if they've been shot by the Castigator. His Tempest Warblade is pretty much identical to the Reaper chainsword, I think. He's 425 points, which makes him the second-most expensive Cerastus Knight, but for good reason.
As for the Cerastus Knight Acheron, he has a lesser version of the Knight Valiant's flamethrower, with the only difference being his 2D6 shots versus the 3D6 from the triple barreled conflagration cannon. Reaper chainfist is exactly the same as Reaper chainsword and Tempest Warblade, move along. He gives the Armigers Fear or something, so anything locked in combat with the Armigers will be forced to take battle shock tests at the beginning of the fight phase, with a -1 debuff. Hmm. Also, any enemy hit by his flamethrower can never have the benefit of cover. Not bad. He costs 385 points, so he's not too expensive.
The Cerastus Knight Atrapos is interesting. His Atrapos lascutter is now a las-impulsor, going up to 36" or 24", depending on your intensity, and with identical Strength, AP and Damage. The Graviton Singularity Cannon has been reworked too, and is now 24", and while he can shoot D3 Strength 16 AP -4 Damage D6+1 attacks that are blast, he can choose to have the Hazardous option, which...only grants him Devastating Wounds. Pass. In melee, the Atrapos lascutter can either make 12 Strength 7 AP -1 Damage 2 attacks, or 6 Strength 14 AP -3 Damage 4 attacks. Armigers get to reroll hit and wound rolls against Titanic or Towering enemies, while the Knight Atrapos himself adds 1 to his hit rolls whenever he targets Monsters or Vehicles...and also 1 to his wound rolls when targeting Titanic or Towering enemies. Whoa! He's cheaper now at 385 points, which is...weird. But I'm not a balance expert, so...yeah. Whatever.
The Questoris Knight Magaera gives an Armiger Ignores Cover. Yay. His plasma-fusil is forever supercharged without Hazardous, and it's rapid fire 2 too! Twin rad cleansers are now anti-infantry 2+. The Lightning Cannon has been nerfed a little, now Strength 9 AP 0 Damage 2, but 12 attacks with Sustained Hits 2 makes it very juicy. You can give him a Hekaton siege claw that's pretty much the Knight Lancer's shock lance, so...okay. Less attacks at 4 and 8, and he only hits on WS3+, though. He also regains D3 wounds during each of your command phase. He's affordable at 390 points. Cool!
The Questoris Knight Styrix also gives an Armiger Ignores Cover and has the same Hekaton siege claw option. What's different? Hmm, his graviton crusher that's anti-vehicle 2+, and his Strength 12 AP 0 Damage 3 Volkite chierovile that spits out 9 shots now, with Devastating Wounds. Tasty. Also, any enemy he shoots his graviton crusher at gets -2 to their Move, Advance and Charge. Oof. He's pretty pricey at 425 points, which is...weird. Why? Mortal wounds with Devastating Wounds? The -2 debuff to Move, Charge and Advance?
The Armiger Moirax is interesting. They are the same as the normal Armigers, but they cost 170 points for some reason, way more than the 145-point Armiger Helverin, even with their exotic guns. Plus they don't have a carapace weapon and have identical stats and invulnerable saves. I guess they get to Heroically Intervene for free? Which isn't what you want unless you have a siege claw that's 4 attacks, Strength 12 AP-3 Damage D6+2, but you really want the guns because there's no sweep option. The conversion beam cannon seems cool, and now you can double up on it. It's only 1 attack each, though, with a 24" range, but is Strength 10 AP -2 Damage 3 Sustained Hits D3, but you get Critical Hits on 4+ when you're more than 12" away from your target.
The Graviton Pulsar is now Anti-vehicle 2+. Nice. Still D6 attacks, not much change, but now only AP -1. The Lightning locks have been nerfed, and though they are Strengh 8 now, they are AP0, but they keep Sustained Hits 2. Still 6 attacks. The volkite veuglaires have been nerfed to 4 attacks each, ugh. They've been buffed to Strength 8, but are AP 0, still Damage 2 with Devastating Wounds. Their siege claws come with a rad-cleanser that's anti-infantry 2+. You can swap for any combination of weapons - even dual siege claws (which gives them 8 attacks but not twin-linked, I guess?). They are very interesting options and provide weapons that the Armiger Helverin doesn't have.
But the Armiger Helverin has 4 Strength 9 AP -1 Damage 3 attacks per autocannon. If you're paying 25 points more, I'm not sure if getting 4 Strength 8 AP0 Damage 2 (even if you multiply it by 2) is worth it, despite Devastating Wounds. Is Devastating Wounds worth 25 points? Or 12 lightning lock hits? Probably that can potentially go up to 16 with Sustained Hits 2, so maybe it's worth paying 25 points for those 8 extra attacks? That said, you might as well go with the conversion beam cannons and graviton pulsars, but then again, the Armiger Warglaive has something similar with his thermal spear? I guess only the lightning locks are worth it...maybe. We'll see.
Anyway, that's all I can say regarding the Forge World index. Have fun, fellow nobles!