As I mentioned, the plot has been done before. On the outside, it's a fairly typical yamato nadeshiko series. Guy finds and takes in a girl with special powers who he starts to develop feeling for, etc etc. The only outwards difference about this one is that the girl happens to be a computer, not a living creature.
Also as mentioned, the series can be quite perverted at times, around the beginning especially. But it does get a lot better. As Chobits gets more into the sci-fi of the plot and more is learned about Chii's past the series can get very enthralling. It's main plot is probably just that the ending is fairly predictable.
The sort of side plot that goes on within the books Chii reads through out the series, A City With No People, also is very cute and interesting while giving clues about Chii's past and what it'll mean for the plot.
In terms of art, it's fairly typical CLAMP: Good with a unique style that isn't so unique that it seems alien to readers. It's very good, almost never off character model. Sadly though, I have to knock a point off as it seems to resort to chibi character models every once in a while.
The characters are probably one of the stronger things this series has going for it. Despite a good amount of them being barely more than steryotypes.
All of them are likable though and each gets their own side plot and "person just for them".
There are two persacoms who appear near the end who don't end really doing much plot wise despite it practically being shown that they were going to be the antangonists. Instead though, the only thing they really do is help resolve another side plot via a small event that could have easily been done another way. If I understand correctly, they have a bigger role in the anime, but even so they just seem unneeded in the manga.
Overall, this is a good series that I enjoyed a fair bit, but it's certainly not without it's flaws. The characters could have more original and developed further, and there wasn't as much done about the sci-fi aspects than there could have been. Also, I may have found a plot hole at the end, but I'll leave that for you to find since it doesn't really affects the series's enjoyability at all.
I give this aborable look at romantic sci-fi an 8 out of 10.
