I have now used Reflow for 2 client prototypes and here is what I have found.

Question

First, I can see Reflow being an incredible prototyping tool if Adobe steps up and makes it a useful tool for production and not just another creative program to help designers build for the web. That's what Muse is for.
So here is my wish list.
Reflow needs to be able to have more control over the DOM elements. By that I mean, we should be able to have a layer based approach (similar to what you can see in Macaw) to move elements around from "box" to "box" (also, can't we just call them "divs"). Nesting is crucial. Also, what's up with all the IDs in the published files? We should be able to name and create classes for these elements before it publishes. Also, support the basic HTML tags for users to control.
On that note, shared elements should have one style sheet instead of a style sheet for each page.
Also, elements should be able to be saved to a library for use on multiple pages. It is a nightmare now if you create an element on a page that needs to also be placed on other pages. You have to recreate it on each page as of now.
Support for common CSS frameworks would be an amazing idea...just sayin.
As for type...Edge fonts and Typekit are great but we all know that there are many other font libraries out there such as Google fonts. Also, being able to use your own @font-face should be an option.
I think the overall goal would be able to use the files produced as a starting point for production code. As it stands right now, the code that is produced will require more time to format properly than it would be to build from scratch.
I know Reflow is not meant to be a Dreamweaver or Brackets, but it could really help set the stage for development in those programs. It can improve the workflow of web development vs. just being a "cool new app". It has real potential and I hope it gets the love that it deserves.

Answer 1

Control over DOM: Yup we're working on exposing this even more. You may or may not have noticed the elements panel already in Reflow. You can find it here:
Are you looking for more than that? We're looking at ways to expose the elements panel in a better way, that should be coming soon.
As for stye sheets all being in one, we're debating this. Since we don't know everything you want to do page-to-page, we're holding off making this leap until we can begin cleaning up what CSS we already give you. (see last answer)
Common library elements: yup, we want  this too. It's on our backlog.
Frameworks: yup again, on our backlog. Are there frameworks you would prefer? We don't wanna play favorites unnecessarily. We don't know how it might be prioritized, since we've got lots of features to get to.
Additional fonts: yup for this one too, we have it on our backlog to tackle. As a note, most google fonts are available in the Adobe Web Fonts.
Output: We're actively working on improving the CSS output from Reflow. We cannot promise perfect production quality, but the issues you raise are all ones we're eager to minimize.
Thanks for the thorough feedback, we love these kinds of posts!
- Seth