Away is a nice engine, far better than using Stage3D direct.
The away foundation is still active but largely focused on Typescript Away and a flash player to play old flash games, AwayFL, evolved from thier work on a TS library that did similar to OpenFL, that was called Away2D?
Rob from Away3D is focusing his team on AwayFL mostly, they are not that actively marketing thier work, I guess they are working to more feature complete release, they have some funding and some talented team-members seems a tie up with an online games portal, but still opensource.
I used Away3D when it was as3 quite a bit. Some greate features, and some talented members. The haxe away3d repo is fairly stagnent now, but Allan says feature complete,
If your using swf material or 2D graphics with haxe Away3D then then it’s a good engine and easy to use and suitable for complex 3D interaction.
Armory is a good solution if you want to integrate with blender it’s fast and seems popular outside haxe community, no idea if it will stay with Haxe scripting. Heaps 3D seems successful on games but likely requires reading source code more than many 3D engines.