I must say I was thoroughly impressed with Construct 2 and the power of HTML5 and WebGL.
The small prototype I made, works smooth at 60 fps, without crash, and from what I saw, I can easily porting the game to the platforms that desire.
From what I observed during my experience with the free version, had one point that were "painful":
1 - The absence of a more complex system for storing/recover data
I think it would be great add support to more complex JSON files, and perhaps support for SQLite3, if possible.
NOTE: Sorry for my english, is not my native language and I'm still learning ^^