You have a really bad case of banding all over the sprite now. Keep the previous edit and move the reflective light to the bottom right of the body rather than the top right. Somewhat like this:
Mine on the left, yours on the right
-You had too many colors, which, although smoothed the values out (which isn't too necessary considering it's metal), sacrificed readability
-The shade on the gray was too close to the blue
-Quite a few jagged lines
-Too much AA on the sides receiving light, giving it a pillowshaded look ( by removing the AA the arms appear thicker also)
-many things didn't seem to be shaded correctly.
I didn't do anything to the one with the porthole, because it's part seemed OK.
Good luck o/
EDIT: Now that I look at it, my darker gray could stand to be darker. Just adding this if it helps