Nice work. For the iOS ones the only one I can really see any meaningful difference for is the iPad one, and for that one I prefer the scaled version as it seems more "blueprinty" to me. As with text, sticking to the pixel grid can cause things to become unexpectedly bold or thin as you change scale. Similar happens to the smallest size icon too, though it's not as big a difference.
Tried it on my iPhone too, but wasn't sure how to ensure 1-to-1 pixel scale, default in Photo viewer seemed like it might be that though.