This week we are going to discuss whether it is better to take power weapons or power fists.
Is it better to strike at your normal initiative with normal strength or to strike at initiative 1 and get double your strength?
First off lets look at some of the numbers. I will use normal marines for both the attacker and defender just to keep it simple. With both weapons you have WS 4, which means that the majority of the time you will be hitting on 4's. This means that you have a 50% chance to hit on each dice roll. Rolling to wound is where the weapons differ. With the power weapon you have a 42.19% chance of causing 1 wound, a 14.06% chance of causing 2 wounds, and because you get the extra attack for the bolt pistol you have a 1.56% chance of causing 3 wounds. For the power fist you have a 48.61% chance of doing 1 wound, 17.36% chance for 2 wounds, and unless you have 2 power fists you cannot get a 3rd attack for an extra close combat weapon. Each weapon ignores armor saves, so this means that on average with the power weapon you will be causing .75 wound per round of combat and with the power fist you will be causing an average of .83 wounds!
While there is a numerical difference in the amount of wounds caused, the two weapons are so close that I feel it comes down to a situational difference in which weapon you choose. Either weapon should perform well against troops, but I think there is a slight advantage of striking at your normal initiative. The power fist is slightly more versatile due to the higher strength, which means that if you need to assault a standard vehicle or are in close combat with a high toughness model, you have a better chance to penetrate the rear armor or cause a wound.
In closing, I think the choice comes down to the way you are going to use the unit and what you are able to allot for in points. I feel that upgrading from a power weapon to a power fist is a great value for just a few more points!