Just my 2 cents
I can say this much after using Construct 2 for 2 years. My first attempt was what I thought to be basic, and ended up being a performance hog. After many attempts, each game got better and better in terms of performance, and the way I handled events. I have learned that there are many ways to achieve things in any game engine, and with that said... just cause you got something to work, doesn't mean it's an efficient way of doing it in relation to your game, and the game engine.
The 3D request seems pointless. C2 is a 2D game creation tool. Period. I feel like if you want 3D, than use Unity.
I will however say that I am displeased with the 3rd party exporters / wrappers. I didn't begin to use construct for mobile development, I came because 1) I'm a visual guy, and 2) saw that it specifically states "Build Once. Publish Everywhere. True multiplatform support. Build your game in Construct 2 and publish it to all these platforms." and Win/Mac/Linux is on that list. Desktop publishing was the deal breaker, for me at least... And doing so currently, is glitchy with Node, and a process for linux and Mac. I feel the request for better desktop publishing is a much needed one. I also really like the spread sheet array idea! Lighting/Shadowing as mention earlier is basically pointless. I feel the ability to establish an actual radius of how far the light/shadow is casted is needed for them to be at all useful.
Really though, everything else is great and getting better. The only REAL issue for me, is the desktop publishing / third party BS. (that isn't Scirra's fault)