Such as great product! I don't know why I didn't heard about this sooner!
One issue that's making it hard for us to use it more widely:
I noticed that images added (via past from system clipboard) are kept in their full resolution. However, they are rendered very poorly due to having no antialiasing. Exported files (except for PDF) also maintains this aliasing issue.
We are planning on building a complex diagram of our software and underlying data flow. We'd like to show the GUI along with the data flow to make it easier for developers and expert users to understand what's happening 'under the hood'.