My stack uses Appcelerator, Rails, and Meteor.
Appcelerator... kind of sucks. But it's much better than HTML5. It performs much better than HTML5, but I find it very hard to write. There's just way too much quirkiness and hacks to make it work. The only thing I like about it is that it's written in JavaScript (but it would be fun to learn a new one).
How does QT compare in this regard?