When glancing at a site like this, I'll give it 5 minutes. Usually the 5 minutes are spent reading headings/paragraphs, watching an intro video, checking pricing / features.

But in this case, I spent the 5 minutes actually using the product. (because that's ALL you can do!)... (which is good)

I like that you don't have to create an account - I was able to get in and start building a site in less than a minute.

I also liked the "Text Style" and "Color Set" pickers. (I like that they're combinations of heading/paragraph styles, instead of having to choose them separately).

I also like that you don't have a bunch of different layouts too choose from. Picking a header image should be enough for most users to start with.

Very impressive!