Also I own 3 new IOS6 devices and Construct's HTML 5 demo games run like crap on them using the built in Safari.
Can you elaborate further on this? The stock Space Blaster demo runs very well on both an iPad 2 and iPad 3 with iOS 6 for me, virtually never dropping below 30 FPS. And at times it has a great deal going on with many animated sprites using blending on-screen at once. What we've seen with mobile devices with preliminary support WebGL is very promising too, since on desktop our WebGL renderer can be 2-10 times faster than canvas 2D and I expect to see similar performance gains on mobile. So I think canvas 2D is perfectly viable already, but support will get even better in future.
I think there may be an effect that since Construct 2 makes it so easy to throw in loads of sprites with its visual editor, you end up giving it more content than even a native engine could deal with. (Canvas 2D in iOS 5+ is hardware accelerated, so rendering probably happens about equally fast as a native engine.) The iPad 3 has quad-core graphics, but a modern desktop graphics card could have around 1000-core graphics... so for some rendering tasks, desktop graphics are literally hundreds of times faster! Do you think this could explain part of the difference?
To everyone else: there's no need to criticise
straybullet, sometimes negative feedback is valuable. Our own forums probably do a good job of filtering out people who don't like Construct 2, so it's rare we hear from them, and there may be things we can do to help resolve the criticisms and improve the product.