I am using starling for UI and away3d.  Works great on PC but on mobile devices the combination is slow ( like most things ).  Using Adobe Scout it basically looks like I am running 2 as3 engines and not much hope for improvement.  Has someone managed to pull this combination off on mobile?  Any tips or tricks?

I am using the shared context method of the two. 
http://away3d.com/tutorials/Away3D_and_Starling_Interoperation

_stageProxy.clear();

_view3D.render();
_ui.render();

_stageProxy.present();

The UI right now is just one starling button and this is just slow.  Scout says starling is around 30 percent of the time spent frame. 

Bullet Physics: vehicle+track
starling +Feathers
Away3D
minmalComps for some debug

I get about 50 fps on Nexus 7

But thats without lights in Away.
Lights just kill it :(

Thank John,  That sounds great.  I would like to hear more on how you got it running so fast.  Ill get back to you with more information.  But it sounds like if you have a static UI that you might see a performance gain with your game if you us the traditional displaylist.  Even in the starling group they talk about the main advantage of starling is making a game with lots of moving sprites.  The displaylist doesn’t have to render on every frame.  When viewing the performance in Adobe Scout that what was bothering me with a starling UI.  You have the really good sprite engine running every frame for a UI that really isn’t doing anything.

I need to get a nexus tablet.  The stats of the Nexus 7 sound like they are better than the IPAD 1 and 2.  So you might see what i am seeing if you test on a lesser machine.