Following a recent conversation on 3++ chat I thought it important to clarify this for the rest of the community. There are significant differences between different combat weapons specifically Lightning Claws (including Wolf Claws) and Power Weapons. Whilst both weapons ignore saves there are distinct and separate cases where they are more useful. This article looks at the specific differences and when each should be taken. Space Marines and their variants have the most ready access to both of these weapons (and more) on Sergeants, special models (I.e. Sang Priests, Wolf Guard, Vanguard, etc.) and characters so there is a lot of thought required to outfit your models. Let’s help out by identifying exactly what each weapon is for.
Power Weapons are sort of the ‘standard’ close combat specialist weapon and have the benefit of getting an extra close combat attack for two close combat weapons (I.e. pistol + sword). This makes it very effective at removing lower T/WS targets which is important for Space Marines in combat mode. Whilst WS/S/T4 generally is pretty damaging to lower WS/S/T models (who also usually have a bad save), the power weapon ads some effective combat punch without costing an arm and a leg. In a close combat army, the power weapon in a squad or single member is generally designed to deal with more numerous foes thanks to the extra attack and efficiency against lower T targets.
The Lightning Claw is a special close combat weapon and therefore cannot gain the +1A benefit for two close combat weapons unless you buy a pair. This is grossly inefficient so you are left with one less attack compared to Power Weapons. This is great when you are using something in your other hand so cannot get the bonus anyway such as a Storm Shield, meltagun, etc. However, the Claw has the added benefit of re-rolling failed wounds. When you run a bit of mathammer you find out this makes the Claw better than the Power Weapon at damaging units at a higher toughness than the user’s strength. Furthermore, they are roughly equal on toughness targets which are the same strength of the wielder and the Power Weapon edges the Claw on toughness targets which are lower than the strength of the wielder.
What this means is the Claw is much better at dealing with high T targets without having to pay the cost for Power Fists whilst also striking at initiative whilst the Power Weapon is better capable of dealing with normal and low T targets. This means, if your army is quite capable of dealing with high T targets through a bunch of Power Fists elsewhere (I.e. Terminators), you may be better off buying Power Weapons on models you are deciding to put a special combat weapon on. On the flip side, if you don’t have much potential to deal with high T targets in combat (I.e. only PFists on Sarges), LClaws might be a better buy for the army.
Both of these weapons also have an advantage over the PFist since they strike in initiative order. Whilst PFists are indubitably better at damaging high T targets such as Monstrous Creatures compared to the LClaw, the LClaw is still capable of whacking around infantry at initiative and is significantly cheaper. In the end a good mix of PFists and either LClaws or PW is the most well-rounded choice for combat oriented units.
This is often why I take LClaws on my Sanguinary Priests. Blood Angels generally are pretty decent at dealing with T3-4 simply through a large amount of S/I5 attacks and although I take PFists on my Sarges to help with MCs/Dreads in combat, the extra 3 LClaw attacks can really make a difference for basic squads against high toughness targets and since most BA armies are combat oriented, making sure you don't get stuck in CC against targets you are unlikely to kill is very important.
