Update: SimpleMind is still marvelous. With the ability to link to docs and URLs, SimpleMind is fitting seamlessly into my current workflow.
Ive had no problems with SimpleMind at all; that extends into the User eXperience where Ive _not_ had to slow down my brainstorming in order to think about how to use the app. It just functions simply and as I would expect. I use SimpleMind regularly in meetings, on flights, in the coffeeshop, etc. anywhere I need to quickly chart out some thoughts without having to pull out a laptop.
The fact that SimpleMind does what its supposed to quietly and effectively gets my stamp of approval, all the other features (sync to desktop, color schemes, export as image, etc.) are just extra gravy.
This app is worth every penny.
Robert Leahey about SimpleMind (Legacy), v1.8.3