Dark Times picks up where Republic stopped, and it means it literally: the inside front cover of issue #1 is numbered 84. Dass Jennir, a Jedi introduced in Republic's final arc, has survived Order 66 by being on the wrong planet, and the book's first question is not how he will fight back but what he is now that the Order is gone.
Wheatley
Doug Wheatley's art is the reason to read it. He draws Star Wars with weight and grime and an almost architectural interest in ships as places people live, and the colouring — dim, brown, wet — commits to the title. Whole pages go by with no dialogue. It is the least noisy Star Wars comic anyone has published.
What it is actually about
Jennir spends the opening arc, The Path to Nowhere, doing something a Jedi is not supposed to do, and the series never lets him off it. The parallel plot follows the crew of the freighter Uhumele, who are not Jedi, do not care about the purge, and are simply trying to make a living in an economy that has just been nationalised at gunpoint. Cutting between the two is the book's best structural idea: the fall of the Jedi as an event most of the galaxy barely notices.
Where it stumbles
Scheduling. The gaps between issues ran to months, twice to more than half a year, and a book this quiet cannot survive a reader forgetting where it was. The Vector crossover in #11–12 also arrives from outside with a Sith artefact and a woman out of the Old Republic, and while it is well executed it is plainly someone else's plot passing through.
Reading it now
Read the first two collections and stop if it does not hold you; the later miniseries assume you care about the crew. It is Legends, it is contradicted by everything canon has since said about the year after Order 66, and it is still the best-looking thing on this shelf.