The Wildcards is the most obviously useful of the three purchasable DLC for Pathfinder: Kingmaker. It adds a new race, class, and two new companions to the main campaign (though only one can be used at a time until the endgame). The Kineticist is a lot like D&D’s Warlock (except instead of having a neutral energy blast they focus on a specific element or elemental combination), and just like that class they start out weak only to become ludicrously powerful at higher levels.
The race and class additions are worthwhile of course, but the companions on the other hand don’t seem particularly well-integrated. It’s also worth noting that the associated companion quests are much more heavily scripted than anything in the base game… which can be either novel or annoying depending on your point of view.
The next DLC at first glance looks like it’s a stand-alone side story (which resulted in my ignoring it until recently). While that’s mostly true, it turns out that your choices there can both change a few things and add a small area to explore in the main campaign. The new campaign is quite a bit different from the main one both in that it’s linear (world map travel is automated) and there’s no time limit (so you can rest as much as you want). It starts you off at level 5 and you’ll reach level 9 somewhere in the final area after about 7 or so hours of playtime; there are three small areas and three large areas not including Varnhold itself.
I played through it once with Neoseeker’s suggested party and didn’t have any trouble (although I’m not sold on the Freebooter). There doesn’t seem to be much reason to play through it more than once or twice due to the linearity, though there actually are a surprisingly large number of choices to be made which can affect how things end.
The third and currently final DLC is both a stand alone and fully integrated with the main campaign. The campaign version is static, bizarrely laid out, doesn’t have much worthwhile loot, has a ludicrous final boss fight, and overall in general isn’t worth bothering with. The stand-alone version meanwhile is almost a separate game: You create a new character and explore an effectively endless number of randomized levels (which is similar in structure to Diablo, down to there being Shrines to activate). There’s no story to speak of here, just killing and looting and unlocking new equipment/bonuses for future playthroughs. So it’s the perfect place to play around with all sorts of different builds if you like the game’s combat system but couldn’t stand the kingdom building or time limit aspects.
I’m on floor 11 at the moment with a Scaled Fist-Eldritch Scion-Paladin, Thug-Aldori Defender-Swordlord-Duelist, Barbarian-Cleric of Gorum, Archaeologist-Vivisectionist-Arcane Trickster, Monk-Tactical Leader (this was supposed to be a Blight Druid… but I messed up the alignment), and a Psychokineticist. The progression so far is a hell of a lot better than the main campaign’s version of the dungeon and I love the randomized loot. So I may end up playing this mode more than the main campaign (of which 2 more playthroughs are planned to grab some more achievements; I started putting together Kingdom Building and Exploration guides to assist in this).
So, surprisingly enough, all three DLC can end up being worth buying depending on which parts of the game you enjoy.