First some praises:
I'm a developer and like to get my hand dirty, and usually like to do most of my coding and rely less possible on frameworks and libraries. As I wanted to expand my reach I started to learn design, and knew it would be a huge new block to learn the modern web and in particular responsive design implementations.
Well I must say this burden was lifted with webflow. It truly a great tool that can get the job done. It's not a gadget you spend your time fighting to get things working. Without even reading any doc I was already capable to do as much, and faster as what I did by hand when it come to implementing design and structure.
Now some remarks:
1) The only thing missing from this product, in my opinion, would be easier access to generated html/css/js code while working. Seems it would be a paradigm shift for you but I think it would be well worth it.
2) I hope the team will continue invest in the "design" aspect of the product, and that it will not be vampirized by the "cms" aspect. I work on complex single page apps and i'll still rely on other hardcore tools for the programming part so i'm not much interested in the 'cms' aspect and probably never will (I speak for many programmers i'm sure).
3) Do you plan to evolve the "design" part, to follow new web standards ? For example, it's possible in the next specification of the html standard, that touch events will be supported. It would be great when those standards are implemented, to have for example new trigger for animation in webflow: "finger touch" and "finger release". Such as what you can do on pinterest native app.
Anyway, this is a very amazing product. It puts design implementation within reach in a remarkable short amount of time.