but I dislike Astro as he appeared in Pluto, especially the fact that they removed most of the things that made Astro 'Astro', such as his signature red boots, his horns or even his "wittle tushie". Uran has the same problem; come to think of it, most of the characters have that problem. I don't mind a bit of character changing, it makes the plot more interesting, but when you've changed the main character LIKE THAT, whats the point!?
I feel that Urasawa didn't necessarily change Atom, but didn't develop him. Actually, we see very little of him in the manga. So we don't see his signature boots or other characteristics because he's absent most of the time. If a person read that manga without being an Atom fan, they would not understand the character or why he is important. Former knowledge is important in reading the manga I think.
As far as styles, it's a toss-up between the 1980's and the 2003 anime. I like the former because he wears clothes. In the latter he looks more lively, but it bothers me he goes everywhere in his trunks. WEAR SOME CLOTHES, darn it!