I have yet to see any benefit from using Unity.
The biggest benefit is that you can reach customers now, not in the future, and you can reach them on:
-PS3
-Xbox 360
-PS4
-Xbox One
-WiiU (proper hardware support, not HTML5 without even WebGL, although not the latest 5.x version of Unity)
-PS Vita
-Native mobile export (if your game pushes CPU limits this might help)
So for bigger games that hear constantly from fans saying "When PS3/PS4? When WiiU?" this service would be awesome.
Plus, 3DS support is rumored to be coming soon, which would be extremely great as well http://unity3d.com/company/public-relations/news/unity-support-new-nintendo-3ds-and-new-nintendo-3ds-xl
I could wait for technology to run HTML5 + WebGL games as well as my Windows desktop can, but in the same time I wait for that the competitor engines and tools are improving too, so a solution that lets me use my favorite game editor to export to native right now is something I would need to keep using Construct 2. After all, this is just a tool to make my game ideas and sell finished games, so the final exported game is what matters most to my customers and hence to me.