Yeah. Lately I've been using MyPaint less and less. :c
Maybe I should draw something in MyPaint, like a B&W portrait or something.
I've used MyPaint, Gimp + GAP, MyPaint, Paint Tool Sai, numerous versions of Photoshop as well as MS-paint for my most fantastics pieces.
Paint Tool Sai or Photoshop seem the best for your art style while MyPaint is for more traditional art methods. Photoshop takes a while to get used to however.