So I ended up deciding to try this and have played a couple of short/early games and one long game with the Sisters of Battle. As a DLC faction, they are well put together, with a solid selection of units and some interesting abilities.
However, this DLC really drove home something that I’ve been thinking about essentially all of the DLC. I understand, in the miniature game context, why adding more factions is great fun: slight wrinkles of squad design and unit abilities to get lost in, new minis to paint, all to bring a unique experience to the next battle. Great. But in the context of a PC game, I’ve become convinced the best overall player experience was with the original 4 factions, who were very distinct and who each captured both the essence of a unique approach to gameplay and also the flavor of the faction. Space Marines brought a great “powered armor infantry” feel to the game. Orks were very Ork-y. Astra Militarum brought the big guns and the Necrons had their funky zombie robot pseudo-Egyptian thing (sounds weird but works.)
And the thing is, I now feel those original 4 factions filled the gaming space of this core game design. For example, the Sisters of Battle are overall pretty similar to Space Marines. Sure, they have interesting wrinkles but in terms of overall gameplay experience, the player got most of this on release with the Space Marines. Likewise for pretty much all the DLC: they might be individually interesting but in terms of overall gameplay experience, I don’t really see them adding much.
It took me a long time to see b/c more DLC sounds “fun” and it’s a Warhammer staple, and yet I think I’ve come to the conclusion that it doesn’t fit this particular game design. Gladius is really a lean, stripped down 4X, and a very good one. Adding what is essentially more cruft to it doesn’t really improve it.
And it’s not just that the DLC don’t really justify themselves as new purchases to me. As I was playing, I would encounter the other DLC factions, and the other additional units they’ve added in their unit packs and the core coolness “Oooh that’s a Leman Russ Battle Tank! Watch out!” is gone. And it’s not just that coolness being lost: I also will look at a unit and go “what is that?” It’s got a little squiggly unit symbol and looks like many other units and I don’t really know what I’m fighting, and, lethally for gamer enjoyment, I don’t really care. “Oh it’s a rounded squiggly vehicle. Better kill it. Oh it’s a square blocky vehicle. Better kill it.”
Big picture: Sisters of Battles individually is a well made DLC. BUT this particular lean, streamlined 4X game design did not NEED all these DLC. And they’ve milked the DLC so hard the game has actually lost something, with the core asymmetry and lean-ness being buried in a landslide of hard-to-parse-the-difference-units and often micro-managey abilities and bonuses.
YMMV. But I think I’ve gotten what enjoyment I’m going to get out of Gladius, full stop (and that was a lot of enjoyment; hundreds of hours) and more DLC doesn’t help.