Webflow is a great time saver without any shadow of a doubt BUT... I am certain it could be even better. Dragging elements and positioning them within the Navigator hierarchy does take time (and precise mouse movement and clicking effort, as well), even more so when the hierarchy becomes quite deep.
I've been thinking, what could be faster than drag'n'drop then? Well, what came to mind is the king of usability in my humble opinion - AutoCAD. After working with AutoCAD, which is set to solve really complex user interaction challenges, every other piece of interface, either online or desktop, has looked dumb and wooden to me... So, how they speed up the work process in AutoCAD is by having a command field and typing commands (which are usually one or two letters long).
It sounds like a lot of hassle - memorizing commands, but it is not. By not having to use the mouse and drag and targer and hit anything, the work process is times faster! Just picture this - instead of dragging an empty div and positioning it somewhere in a deep Navigator hierarchy, you typed something like "ins div" and immediately, a div appeared under the currently selected branch.
Well, you could say you could achieve the same thing with keyboard combinations. Keyboard combinations are not exactly the same as commands, but if this helps you get the idea, you can think of it as this way, too.
Another reference points (which I have not used myself, though, is VIM (http://www.vim.org)).
So, please, please do not disregard this suggestion as far-fetched, because we are talking about huge savings of time here. Do talk to people who work with AutoCAD to confirm the usefulness of commands!