What's great
Subframe has become my #1 design solution. (Sorry, Figma.) It enables me to create what I'm envisioning without having to worry about how much frontend dev work it's going to require. They've solved the handoff! I've been designing websites since we were all copying source HTML from Netscape and pasting it onto notepad to learn how to nest tables, and this is the first time I felt like a tool is actually built to address the technical aspects of web design.
What needs improvement
There are a few quirks, like still needing to insert Tailwind CSS for gradient backgrounds, so if you're strictly a designer who doesn't know much frontend, that could be a challenge. But the founders are super engaged with the community, so they'll help you out pretty much right away.
vs Alternatives
FigmaSubframe makes the handoff from design to frontend dev so seamless that it's practically not a thing anymore in my workflow. Having lived through the pain of getting my designs translated into code incorrectly by plugins that would hurt more than help (or frontend devs who didn't see why using a 12px rounded corner vs an 8px rounded corner was such a big deal), Subframe is solving a legitimate pain point. I'm excited to tell people about it every chance I get. It's made it possible for me to iterate and test my designs on browsers with real people literally within hours.