Now, some details: First off, GitS Arise: Alternative Architecture (or GitSA:AA) is a more-concise version of the four GitS: Arise movies, which basically focus on the creation of The Major's team (which eventually becomes the core of Public Security Section 9) plus an additional two episodes of new content at the end. But bizarrely, the first two episodes in the GitSA:AA series are the (trimmed-down) final Arise movie, Border 4: Ghost Stands Alone - in other words, the series starts with its climax, spoiling itself right from the start for people who haven't watched the movies yet. That disorder is the main reason for my low rating for GitSA:AA; my rating for the original Arise films is higher, as they are the same good story but presented in a sensible narrative order. GitSA:AA is an alternative architecture, all right: one that puts major components in the wrong places, resulting in the failure of the structure. (Insert collapsing-bridge image here.)
So if you haven't watched the four Arise movies yet, I'd strongly recommend watching them first, and then just watch GitSA:AA episodes 9 & 10 followed by GitS: The New Movie (2015). Or if you'd rather watch the abbreviated version of the story, start GitSA:AA with episodes 3-8, then watch episodes 1-2, and finally watch episodes 9-10. You'll be glad you did! Either way, if watched in the correct narrative order, I would recommend these stories, especially for fans of the Ghost in the Shell franchise.
Aside from the bizarre re-ordering of the story here, this is a good series overall. It's hard to compare this series (or the Arise films) against the GitS: Stand Alone Complex / 2nd GIG series, which is a masterpiece and (in my view) the best anime of all time. The original series' depth of writing and characterization, exploration of existential and other thought-provoking themes, and brilliant filmcraft, all make a fair comparison impossible. Still, the Arise stories feature competent, character-driven writing. Although this series can be seen as an alternative continuity to the original series (which itself was a bit of an alternate continuity to the original 1995 GitS film), even the idea of different continuities without a "privileged" continuity can be seen as yet another facet of the existential themes that are at the heart of Ghost in the Shell.
The characters are a bit different here: better in some ways, sure, but perhaps worse in others. And if you watch the English dub, it can be hard to get used to the different voice actors. But the series fleshes out its characters pretty well and does a bit more for side characters like Ishikawa, Borma, and Paz than Stand Alone Complex did, providing some additional (and in many cases alternative) detail in their implied backstories and more meaningful screen time. And if you finish the series with GitS: The New Movie (2015), you'll get a satisfying conclusion to the overall Arise story.
In short, GitSA:AA is worth a watch (again, assuming you watch it in the proper order to avoid the spoilers).
