Before we begin with this review, allow me to explain that I have NOT seen Eureka 7. Many people who love the wildly popular anime say that it is very similar to Xam'd, but a great anime. Understand that people who think that Xam'd is just a copy of their favorite anime, still admit that this is a great anime. Hold that in mind while reading this.
Story was a tricky part of the review to write. If I could break it up, the first half of the anime was a 7/10, and the second half was a 10/10. The beginning half of the series was fairly slow paced and the events that occurred made you come to hate Akiyuki, the main character. Not only was he a snobby, idiot, he just managed to find himself "coincidentally" in the line of plotline action time and time again. It just wasn't a very fun use of storytelling.
That being said, once the second arc opened up, everything changed. Akiyuki transformed into a deep, intelligent character, and every other character followed suit. The storyline starts to show action, and blossoming romances, and the ending few episodes are a tour-de-force of action, and amazing plot lining.
Flawless. That is the only fragment I could write when asked to describe the animation of Xam'd. Gorgeous skylines, amazingly fantasty elements. Unique monsters were something that pulled in alot of viewers to my understanding, but the human designs were what kept me. Distinct, yet clean; a very healthy "median" of animation.
The sound was above average, but not the best for the series. Good opening and ending songs carried the anime, and the actual sound recording for the action scenes were very realistic. However, since the first half of the series was so slice-of-lifey, the sound was unmentionable until halfway through.
The characters are what kept me personally interested in the series. Every character goes through a transformation in the series, and ends up a more mature version of themselves in the end. I'd like to term the phrase "plotline puberty" for such an event. Every single character had annoying qualities in the beginning, and shed them off systematically before the series was over. This is a very hard thing to do, and rarely seen in the anime world (outside of the obvious fan favorites that have gotten so because of reasons like this).
The only reason I didn't give it a straight up 10, was because the characters are the beginning were so flawed, it was almost annoying. One of the characters, Ishuu, was the ship captain, and was just such a horrible character at first. Smoked heavily, reclusive, and would slap Nakiami when Nakiami didn't do what Ishuu wanted exactly. It showed much too much immaturity for a woman of her fame and talent. (Albeit, some may think this was just a plot to later show the caliber of her character change, but I can't help but by annoyed by it. Early Akiyuki was just freaking dreadful. I hated him, and watched the series to the other characters until halfway through.
Overall, the only flaws this series had were personal choices for myself. If I were to be unbiased, I think I might have given it a perfect score. It was just a very well rounded, intelligent anime, with loads of great dialogue, abundant character development, amazing animation, and a semi-unique plotline that I won't forget. I severely recommend this anime to anyone who wants a more mature series to watch.