Void Shadows is one of the best DLCs Owlcat has ever made for one of their games. It is so good that I am willing to overlook they delayed it from the original release date when I preordered Rogue Trader. It is a master class of using time efficiently to polish a product and deliver something of exceptional quality.
This review is based on patch 1.2.1.17; there have been many bug fixes since then, so keep that in mind. For additional context, I did a Heretical and Iconoclast run in base Rogue Trader without DLC and a Dogmatic run with Void Shadows enabled. I have also 100%ed the game.
Writing-wise, this game is spectacular, and you can feel the love of lore in every syllable spoken and written in the game. It shows great respect for 40k as it has been, and as a long-term fan disappointed with many of the changes to lore recently that throws out established canon, I am pleased to tell all 40k fans that this DLC is well worth supporting.
As a 40k fan going back many years to 2nd Edition, and someone who enjoys learning the lore as a hobby, I have experienced many twists and turns in Void Shadows that have exceeded my expectations. Well done to Owlcat. The new companion is exceptionally well written, with a compelling backstory that is true to lore. On the battlefield, she can solo entire mobs by herself if kitted out right. She is a fantastic addition to the game in every way, and I found myself agonizing over who to cut during my companion quests to bring her when I had to bring some of the less useful companions.
In terms of gameplay, all of the new enemy types, characters, and choices you get to make work seamlessly within the Koronus Expanse and the existing game. I did a deathless run on unfair and found the battles to be challenging at times, even with min-maxing my builds. I really had to think carefully about what I was going to do, even more so than in the original game.
I only encountered a few bugs with a couple of the quests, and some of the items for cargo show on the map but cannot be picked up. I used the bug report feature liberally to help Owlcat iron them out. Unlike base Rogue Trader early on, I did not have to use the Toybox mod once to get a quest finished. I did all the Void Shadows DLC quests, companion quests and base quests successfully. I feel satisfied that this is worth the price Owlcat wants to charge for it. A lot of love and work clearly went into the making of this DLC.
My only complaint is that the final boss hitched frames all over the place; it did not do that the first couple of times I fought and defeated it. I did report this as a bug, and my PC is high-end and ran flawlessly otherwise throughout my 3rd run in Rogue Trader.
Overall, I strongly recommend that any true 40k fan get both this game and the Void Shadows DLC. I am eagerly awaiting the next DLC and hope Owlcat continues making DLC of this calibre. If they do, Rogue Trader's future is bright, and it will make it one of the few not-middling 40k games. A very worthwhile DLC I rate as a 9/10, only because of some framerate issues and small bugs.