I highly disliked Jing. Of all the series I've watched so far, I have seldomly experienced such hardships struggling to make it through a show. I'm not saying the official site review is bad, not at all, as this is largely a matter of personal taste. I just thought it could be useful to present another perspective; not everyone thinks this show is awesome.
As for the story, because it's almost entirely episodic and random, there isn't really one. Watching Jing, I discovered that I hate episodicness. I totally didn't care about what happened or what was going to happen, because it was random, enemies were not appealing and even fighting scenes didn't manage to capture my attention. I also discovered that the kind of random humor in Jing is totally wasted on me, while I usually laugh myself to tears in shows like Ouran High School Host Club, One Piece and even Clannad from time to time (it's not like I'm humorless xD). This takes away the few things that actually make Jing enjoyable for other people and made it into one of the most painful experiences I had to endure in anime world.
The animation was about the only good thing about this show. The character design of Jing was brilliant; up to the messy hair, yellow coat and big shoes it reflected his laid-back personality perfectly. The landscapes were also nicely done. The Jing-Kir transformation sequence was tiresome, though. On top of the fact that the attack almost never worked and occurred 10 times in every episode, it was green coloured. WHY?
I didn't really like the music, but the Opening Theme was, although not in accordance with my personal taste, a good fit for the relaxedness the show breathed.
Although I found the characters generally uninteresting, Jing made me smile on a rare occasion. On top of the brilliant character design, I didn't dislike his laid-back personality either. Kir also had his moments of throwing in cynical remarks. The rest of the cast only had a chance to shine for 1 or 2 episodes, and as a result nobody did shine at all, although the little bomb-creatures were cute. Anyway, Jing himself probably was the best part of the show for me; he saved the show from getting a mark lower than the 5 it got now.
Maybe I shouldn't be complaining as harshly as I am now. If you don't enjoy episodicness (like me), you'll find the total show a tragic waste, while it may actually be not quite as bad as it seems, especially if you happen to enjoy the random humor. I think this show is, even more than other shows, really heavily dependant on specific personal preferances. As for me, I can conclude that this show thoroughly bored me. That's all.