Web games are great ! All my favorite games are native, ops!
I don't really like the current feeling of playing games in a browser. This could change though.
About Stencyl yeah reach wise they're way ahead of C2. Exporting HTML5 games unfortunatelly right now doesn't translate to covering all platforms. By covering i mean don't only reaching but running well. So if they've got the resources to trully exporting to all platforms they have the advantage in that aspect. However , their IDE falls short compared with C2's.