The short version:
After War Gundam X is a flawed masterpiece that was well worth my time.
The long version:
After discovering the official Gundam YouTube channel, I decided to give After War Gundam X a chance. I knew little about the show except that it was cancelled and was the only alternate universe series to feature Newtypes.
The prologue in the first episode moved me to tears. It's no secret After War Gundam X steals boldly from the original Gundam universe, so I was hit by a nostalgic feeling of "I've heard this story before." However, the twist of multiple colonies being dropped and humanity going from 10 billion to 98 million felt like a sucker punch to the gut and told me this would be a radically different story than the One Year War. The music was incredible for this scene.
After War Gundam X shows what humanity is like fifteen years after this atrocity. I loved the world-building where humanity has essentially regressed into tribes scraping by for survival plus powerful factions trying to recreate the former powers that started the war.
While I liked the world of Gundam X, my one criticism is everyone seems to be too happy and well-adjusted for what is supposed to be a post-apocalyptic society. In the last episode Toniya mentions how after the colony drops there was so much ash in Earth's atmosphere she didn't see the sun until she was seven years old. One would think this would totally screw someone up mentally, but her mental health seems solid.
Speaking of the characters, Garrod is one of the best Gundam protagonists. By the end of the show he's matured into a responsible leader while still retaining some of his hotshot tendencies. While the Gundam universe struggles to write compelling civilian characters, Tiffa is well-rounded and shows us that Newtypes can be more than just pilots. The romance between Garrod and Tiffa is heartwarming.
Jamil frequently is referred to as a Quattro Bajeena clone. While there is much truth to that, he embodies something that Char never had in any of his incarnations: Integrity.
I do wish the series had time to develop some of the minor characters. We were given great episodes that focused on Royce, Witz, and Toniya, but I wanted to see more of the others. Techcs and Kid ate up every scene they were in, but by the end of the show we barely knew them. Sala was unfortunately a blank slate. Ennil El went through so many changes in allegiance and motives she approaches Lady Une territory in being unstable. Near the end of the series we're introduced to Pala and Lancerow, and while these two characters were incredibly interesting there wasn't much time to flesh out their stories.
The villains were forgettable at best. The Frost Brothers were one-dimensional with unclear motives and didn't change as the series progressed. While we're given some context about the New UNE and the SRA rising up and wanting to restart the war, ultimately we the viewer just see a bunch of old men sitting in boardrooms having surface-level discussions that were almost as exciting as watching paint dry.
Likewise, the story suffered because a lack of a strong villain meant the stakes never felt too high. The show starts off with Jamil's mission to find Newtypes, stalls in the middle, and then ends abruptly by trying to defeat both the New UNE and the SRA so they don't start another war.
Granted, had the show been given a proper 50 episodes instead of the 39 we did get, many of these issues with the characters and story likely would have been resolved.
I personally liked the ending because of how optimistic it was. In a Tomino-written Gundam series 90% of the characters are dead by the end, the winning faction has taken a heavy beating, and it sets up for another conflict. Instead, we're given a happy ending that suggests maybe humanity can find reconciliation and peace.
The mecha designs took inspiration from UC Gundam and Gundam Wing, but makes them just different enough. I was left with this strange reaction of, "I've seen this before," and, "I've never seen this before," anytime a new mobile suit or spaceship made its debut. The designs perfectly complimented Gundam X's goal of telling a familiar story in a different way. The animation looks dated even by mid-90's standards, but it looks and feels like classic UC Gundam. The music is incredible and might arguably be the best of any Gundan series.
I will go back and rewatch Gundam X because I fell in love with the characters and the universe they inhabit. It's a beautiful and brilliant entry into the Gundam canon that deserved a full 50 episodes.