Why the sex change.... Why must Denkou be turned into a girl for the dub version? Now we get into the root of Astro... Why did they stop The Neon Express?
I sometimes like to watch anime with both the English sub and dub. There are often differences between the two that are quite funny.
The main character in Metropolis manga was able to change sexes at the push of a button, but the film made it a female. I guess it was too weird or perhaps contributed too little to the plot to make it to the big screen.
I haven't seen the dub, but that's an interesting change. I understand that Epsilon/Photar in the 80s English dubs have the character as male in Australia and female in Canada. Of course, when it comes to robots there can always be some degree of androgeny, especially when all you have to go on is the voice.