Retributor squads remain largely unchanged from the White Dwarf codex, though they did take a pretty sizable hit. This came in the form of a global change to Acts of Faith; now they can only gain Rending for one Shooting phase, as opposed to trying every turn. For this squad you just have to take a Simulacrum Imperialis because their Act of Faith is so central to their effectiveness as a squad, especially if you take either heavy bolters or heavy flamers. All the unit upgrades have the same tweaks in cost as the others and each Sister costs the same as a regular Battle Sister. Essentially, it is the same as the Battle Sister unit from the Troops section, apart from in squads of up to ten, rather than up to twenty, and can take four heavy weapons with no special weapon options. My opinion? Take a squad of ten Sisters with a Simulacrum Imperialis and either four heavy bolters or heavy flamers, depending on your poison. If you want anti-armour, take a Dominion squad with meltaguns instead of Retributors with multi-meltas.
The same armour as a Space Marine Predator tank, choice from the Adepta Sororitas Vehicle Equipment list, the Shield of Faith global rule and a Strength 8, AP1 Heavy D6 48″ range gun. Wow. Take them. Take two. It would have been nice if Games Workshop had given them the option of getting Skyfire, as the codex has absolutely no anti-air by itself. This tank was a competitive choice before and it remains so and even for fluff-based armies like mine, it will be right at home as it is the main, and only, battle tank for the Sisters. There is not much more to say concerning this. It is good and should always be taken. It should also be noted that this is the only thing in the entire codex with a 48″ range.
Last, and unfortunately least is the Penitent Engine. By no means is this a bad choice as it is only slightly more expensive than a Razorback, but it is competing with two very solid units. Taken in squads of one to three and wielding dual Dreadnought close combat weapons with built-in heavy flamers with the Rage, Shield of Faith and Unstoppable special rules; if they get into close combat with something, they will hurt it a lot. However, getting into combat may prove problematic as this walker only has armour value 11, 11, 10 with the Open-topped special rule. They are incredibly fragile, but hit like a truck in close combat, or even just using twin heavy flamers to burn things. If you’re looking to be really cheap, or if an opponent needs to learn a lesson in humility, take nine of them in a 1000 point game. You can fit nine into 1000 points, but this would be considered rather cheap. Their drawbacks are that they are incredibly fragile and only have Initiative 3, meaning that a squad of Space Marines may just wreck you with krak grenades before you even get a chance to strike at them in close combat. This is very much a unit that falls under the category of ‘take if you want to’ as they can have amazing games where they tear through all manner of opponents, or they can have bad games where they just die in turn 1 or 2.