I'm having trouble putting it all into words, but I do notice some subtleties that allows this one to stand out from the previous version a bit. For starters, I do find Sailor Sun's body language to be a bit more 'heroic' with this version, although I'm not quite sure if it's because she's closer, her shoulders are straighter, or a combination of the two. Still, it's a nice touch.
One thing I can say for sure is that I agree with you in terms of the lighting. It appears as though you were more comfortable with the coloring process of this version, and as a result, you were able to give the image a more unique look.
All in all, though, I do think this is an improvement. If nothing else, this piece shows a clearer direction in what you wanted to accomplish, which seems to have resulted in a fresher take of the drawing. Nicely done!