Ya, I don't really like aa in pixel art either, it kinda defeats the purpose of "pixel" art. This piece do's look good without aa.
I'm not a huge fan of AA just for the sake of AA with pixel art. If you just kill the white/gray outline pixels completely it looks really good.
Well, it looks alot better on a white background considering you aa'd it accordingly. (Open up a graphics program and paste it and you'll see.)
It is a pretty cool sprite, but I reccommend that if your going to aa a piece, leave the background the color you aa'd it for.
Good job anyway.