Got an invite to play with it and it’s pretty impressive. Easy as pie to make changes and virtually idiot proof for clients to edit their own content. Integration is a few code snippets to the areas you want make editable. Some negatives for me is the fact that it’s not self hosted, Drop Box is the only way to serve site templates - there is no ftp. $18 per month is a bit steep, I think a price point of $12 would hit the mark.
I received my invite too and I agree, it’s a very smooth piece of kit in many ways. As Marcel said, the lack of self-hosting is also a problem for me but generally it looks and feels very professional. A big step-up for an in-page editing CMS (though MojoMotor isn’t too bad in this regard), though not as nice as Barley. I’ll be interested to see how it’s received when it gets released into the wild.