All of your works seem to have a rather colorful palette. Its great but sometimes it gets a bit annoying.
I think your 50/50 dither is fine. No, it's nowhere near as technically skillful as Helm's work, but you used an effective technique to simply add a few new colors without increasing your palette size. The illusion was opaque to me--as I said, I had to zoom in to realize it was only RGB--so I call it a complete success. This doesn't feel like an RGB restricted palette, that's what I like. The only exception is bright greens and blues around his/her lower back.
[EDIT] Also, you used some nice line-dither in the reds on the lower half of the image. So more than just 50/50!
@Hatch: Now that you mention it, yes I'd seen it a long time ago but didn't quite remember it. Cryptomnesia at it's finest, I guess! However, Helm's not only more skilled overall, but got a true grasp on dithering (while I only applied the easy-to-remember 50x50). Seeing the comparison now makes me want to improve this 
definitely a favorite
I have no idea what is going on in this picture.