You might want to try my Qt C++ app[1], which is very performant, has a block-based editor, and simple to use. Currently, no Latext support, but it's in the bucket list.
{{image "source":"file:///Users/ruby/Downloads/myimage.png"}}
{{/image}}
1. Having complex blocks such as a Task Board/Kanban right within the middle of a document. And more type of such blocks will be implemented in the future (code blocks, LATEX support, etc)
2. You can drag and drop any block, where the dragged object simply "pops" from its place and the rest of the blocks makes room for it.
3. It's blazing fast at loading large documents (See our War and Peace test on the website).
4. The UX of using the "/" slash character to insert block types is very fluid, with instant search results, you should give it a try.