I havent tested Stingray, but from what I have seen, the UE4 has a much better graphic quality -> https://forums.unrealengine/showthread.php?58385-Koola-s-stuff&highlight=koola 
Edit: https://forums.unrealengine/showthread.php?89991-Unreal-Engine-Or-Autodesk-stingRay-for-architecture-visualization
Just saw your other thread, will close this one 