Hi,
As for today AIR / Away3D / Stage3D anti-aliasing of 3D-content is disabled for all mobile devices on the runtime-side.
This means that the edges of your 3d-object will always be jagged on a mobile device, no matter what value you set on View3D.antiAlias property. On HiDPI devices (e.g. Retina Display) the jaggedness is less obvious, but still clearly visible. And no, you currently can’t make this better, i.e. “supersharp”.
You could use a FXAA-filter, but this solution doesn’t make runtime-side-anti-aliasing redundant. The only filter I could find for Away3D is this one, shared by iY0Yi:
FXAAFilter3D: https://gist.github.com/iY0Yi/9214675
Filter3DFXAATask: https://gist.github.com/iY0Yi/9214656
There is a new feature-request on Adobe Bugbase concerning stage3D anti-aliasing on mobile devices I would strongly encourage you to vote for:
https://bugbase.adobe.com/index.cfm?event=bug&id=4101164
Thank you.