We are evaluating Webflow as a rapid development tool. My initial feedback I see others share: it would be really nice if there was the option for it to generate Bootstrap compatible code, in part because of all the elements available for Bootstrap.
I really like how your product naturally feels like Photoshop, so the gui was very easy to pick-up. However, for users who understand the structure and usually work in a text editor, some things like changing the default link style, are not obvious.
Better text-based documentation targeting advance users would be nice. I found the videos very painful to listen too, as the was a lot of unnecessary information and they were quite repetitive. Great for beginners, but frustrating for more advanced users. For example, I would like to have been able to check documentation to understand how to answer the row question I asked separately.
There is a lot of promise in your product, hope this feedback helps.